Synthesis of highly concentrated,carrier free ^188Re—mercaptoacetyltriglycine

Chelation of ^188Re to compounds such as MAG3 will further reduce the radiation dose to the patient in case of balloon rupture through the rapid excretion from the body.In order to prepae highly concentrated,carrier free ^188Re-MAG3,Sbenzoyl mercaptoacetyltriglycine(S-Bz-MAG3) was synthesized.labeled with carrier free ^188Re.the overall yield of S-Bz-MAG3 is higher than those published in the literature,Dependence of the labeling yield of ^188Re-MAG3 upon concentrations of reducing agent,pH,reaction time,etc.was examined and optimum conditions were confirmed.The concentration procedure was succeeded with Sep-Pak C18 cartridge to obtain highly concentrated ^188Re-MAG3.In the case of optimun conditions.the labeling yield of 188Re-MAG3 was more than 98%.Radiochemical purity of ^188ReMAG3 was more than 92% after 24 hour storage at room temperature.     

The magnetic field design of a solenoid for the cold-cathode Penning ion source of a miniature neutron tube

A high-yield and beam-stable neutron tube can be applied in many fields. It is of great significance to the optimal external magnetic field intensity of the cold-cathode Penning ion source(PIS) and precisely controls the movement of deuterium(D), tritium(T) ions and electrons in the source of the neutron tubes. A cold-cathode PIS is designed based on the solenoidal magnetic field to obtain better uniformity of the magnetic field and higher yield of the neutron tube. The degree of magnetic field ...     

Time-dependent radiolytic yields at room temperature and temperature-dependent absorption spectra of the solvated electrons in polyols

The molar extinction coefficients at the absorption maximum of the solvated electron spectrum have been evaluated to be 900,970,and 1000 mol~(-1).m~2 for 1,2-ethanediol (12ED),1,2-propanediol (12PD),and 1,3-propanediol (13PD),respectively.These values are two-third or three-fourth of the value usually reported in the published report. Picosecond pulse radiolysis studies have aided in depicting the radiolytic yield of the solvated electron in these sol- vents as a function of time from picosecond to microsecond.The radiolytic yield in these viscous solvents is found to be strongly different from that of the water solution.The temperature dependent absorption spectra of the solvated electron in 12ED,12PD,and 13PD have been also investigated.In all the three solvents,the optical spectra shift to the red with increasing temperature.While the shape of the spectra does not change in 13PD,a widening on the blue side of the absorption band is observed in 12ED and 12PD at elevated temperatures.     

Low Energy Plasma Focus as an Intense X-ray Source for Radiography

Study on X-ray emission from a low energy (1.8 kJ) plasma focus device powered by a 9 μF capacitor bank, charged at 20 kV and giving peak discharge current of about 175 kA by using a lead-inserted copper-tapered anode is reported. The X-ray yield in different energy windows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry is found to be (27.3±1.1) J and corresponding wall plug efficiency for X-ray generation is 1.52±.06%. X-ray emission, presumably due to bombarding activity of electrons in current sheath at the anode tip was dominant, which is confirmed by the pinhole images. The feasibility of the device as an intense X-ray source for radiography is demonstrated.     

Paleodose evaluation of porcelain: a practical regression method of saturation exponential in pre-dose technique

1 INTRODUCTIONPre-dose dating of the porcelain was reported by St...ham[1] as early as 1983.Just as pointed out by BandZ], it is a technique requring considerable experimentaleclats to yield dose estimates due to the complexity of the pre-dose effect on which it isbased. The basis of pre-dose techlilque is the measu-rement of the change in sensitivity of110"C TL peak in quartz. The 110'C peak has a half-life of only several hours at roomtemperture though it does not occu-r in natuxal T…     

One step graft copolymerization of acrylic acid and sodium styrene sulfonate onto high－density polyethylene film by preirradiation method

High-density polyethylene(HDPE)films were irradiated by ^60Co gamma ray with a dose of 100kGy in air and then immersed in aqueous solution of acrylic acid(AA) and sodium styrene sulfonate(SSS) at different temperature.The effects of grafting conditions such as temperature,reaction time ,Mohr‘s salt concentration,and total concentration of monomer on grafting yield were studied.Both grafting yield of AA and SSS onto HDPE respectively increases with total concentration of monomer on grafting yield were studied.Both grafting yield of AA and SSS onto HDPE respectively increases with total concentration of monomers.The highest grafting yield was observed at 3mol/L monomers where the grafted PE swelled to the largest extent in the monomers mixture.The grafting yield increases with reaction time and then levels off.At higher temperature,the grafting yield decreases with Mohr‘s salt concentration,but increases at low temperature when Mohr‘s salt concentration is 0.083%.Which can be interpreted that in the presence of Fe^2 diperoxides and hydroperoxides may decompose at low temperature to form radical which can initiate the grafting.The physical and chemical properties of grafting films were also investigated.     

Verification of neutron-induced fission product yields evaluated by a tensor decompsition model in transport-burnup simulations

Neutron-induced fission is an important research object in basic science.Moreover,its product yield data are an indispensable nuclear data basis in nuclear engineering and technology.The fission yield tensor decomposition (FYTD) model has been developed and used to evaluate the independent fission product yield.In general,fission yield data are verified by the direct comparison of experimental and evaluated data.However,such direct comparison cannot reflect the impact of the evaluated data on ap...     

Experimental study of triplex-forming oligonucleotide targeted to the initiator of S gene of HBV labeled with 125Ⅰ

This study is used to investigate the feasibility of employing the Iodogen method to label triplex-forming oligonucleotide (TFO) targeted to the initiator of the S gene of HBV with 125Ⅰ. A 17-mer oligonucleotides sequence was synthesized and grafted at the 5' terminal with a tyramine group. Radioiodination of the tyramine-TFO with 125Ⅰwas then performed using the Iodogen method. After TFO was labeled with 125Ⅰ using the Iodogen method, the labeling rate, the radiochemical purity, stability and bioactivity were determined, respectively. The results show that the radiolabeling rate and the radiochemical purity were 93% and 99%, respectively; and the radiochemical purity is more than 90% in vitro at -20℃ on the 5th day after labeling; and the rate of 125Ⅰ-tyramine-TFO binding to HepG2.2.15cells was (37.2±1.4) % and statistically different from the rate of HepG2 (p＜0.5). Hence, it is concluded that the labeling of oligonucleotides conjugated with tyramine using the Iodogen method is successful and is characterized with a high labeling rate, high stability, and a low loss of bioactivity of the labeled agent.     

Influences of frequency on nitrogen fixation of dielectric barrier discharge in air

The influences of frequency on nitrogen fixation of dielectric barrier discharge in air were studied by electrical diagnostics, gas detection and infrared detection methods. The system power, nitrogen oxide concentration, voltage–current waveform, dielectric surface temperature distribution and filamentous discharge pictures were measured, and then the energy yield was calculated; paper studied their changing tendencies in the presence of frequency. Results show that frequency has strong influences on nitrogen fixation. When the parameters of reaction chamber and amplitude of applied voltage is fixed, with the increasing of frequency, the system power increases; in 5-10 kHz, nitrogen oxide gas concentration up to 1113.7 mg m~(-3), and 7 k Hz is the optimal nitrogen fixation frequency whose energy yield is 20.5 mg(m~3 W)~(-1).     

Preparation and biodistribution of 186,188Re—HEDP for bone tumor therapy

Radionuclides^186,188Re,suitable for tumor therapy and with high specific activity,are prepared through irradiating natural metallic rhenium,instead of costly enriched target,Complexation of rhenium with HEDP(1-hydroxy ethylidene diphosphonate)is mainly dependent on pH values and the reductant concentrations in the medium,and the yield is not less than 0.95 in pH2.0-4.0 and SnⅡconcentration of 0.012-0.018mol/L.The 186,188ReHEDP complex has high stability in vitro and in vivo in the presence of protecting agent,and gives superior biological properties in small animals,similar to those of ^153Sm-EDTMP including faster blood clearance,lower soft tissue residue and higher skeletal uptake with the peak of 0.2576 ID/g at 1h post injection(overseas report 0.0101 ID/g)comparable to that of 153m-EDTMP(0.2644ID/g) at 3h post injection.     

^186Re标记博莱霉素的研究

采用Ｓｎ（Ⅱ）还原法，系统研究了反应条件对＾１８６Ｒｅ－ＢＬＭ形成的影响，结果表明：ｐＨ值对络合物额影响最大，以葡萄糖酸钠为保护剂，可避免反应过程中铼的重新氧化，并建立了ｐＨ３－４．５时产额达９８％的制备条件。     

MAG3在放射性金属标记应用中的最新研究进展

综述了利用巯乙酰基三甘氨酸(MAG3)标记的多肽的生物学特性。经MAG3形成的^99Tc^m标记物的标记率和比放射性高,体内稳定性好,与血清蛋白的非特异性结合低;经MAG3形成的^186/188Re标记物也具有良好的体内外稳定性。     

用质子加速器生产医用放射性同位素^186Re的计算

计算并预估了用中国原子能科学研究院最近建成的质子强流回旋加速器生产医用放射性同位素＾１８６Ｒｅ的产额和放射性活度，对质子能量和辐照时间的选取提出了建议。     

从氘束照射后的186W靶中分离无载体186Re

以188Re为示踪剂测定了N-235对铼酸根的萃取曲线,及硝酸溶液和氨水溶液的反萃曲线,获得了萃取分离的最佳条件.采用酸性Al2O3柱和萃取方法联用的放化分离流程,成功地将无载体186Re从氘束照射过的186W同位素靶中分离出来,并经蒸干、灼烧等处理,最终制成了可供标记用的无载体186Re生理盐水溶液.186Re的总放化回收率约85 %.     

188Re直接标记抗体方法研究

以2-巯基乙醇作为抗体的还原剂,葡萄糖酸钠作为中间弱配体,在pH5．0的条件下,以SnCl2快速还原”。ReO4^-,进行了单克隆抗体IgG的直接标记。探讨了影响标记率的因素。结果显示,优化后的标记条件为pH5．0,室温下标记3h,SnCl2用量2．66μmol,葡萄糖酸钠用量80μmol。该方法操作步骤简单方便,标记率较高,为94．4％±0．7％,标记物不需分离纯化,且有良好的体外稳定性,室温下可稳定保存8h。     

186W(d,p)187W和186W(d,2n)186Re反应激发函数评价及厚靶产额计算

考虑特征γ射线分支比、衰变常量和标准截面等修正,对氘引起的核反应¹⁸⁶W(d,p)¹⁸⁷W和¹⁸⁶W(d,2n)¹⁸⁶Re的激发函数进行了研究。收集并分析了这些反应激发函数的实验测量数据,应用数学方法对分析处理后的实验数据进行了拟合。同时,采用TALYS程序对这些激发函数进行了理论计算。经过综合评价,给出了50 MeV以下¹⁸⁶W(d,p)¹⁸⁷W和¹⁸⁶W(d,2n)¹⁸⁶Re反应激发函数的推荐值,利用得到的¹⁸⁶W(d,2n)¹⁸⁶Re激发函数推荐值计算了医用放射性核素¹⁸⁶Re的厚靶产额。     

Measurement of 186W(4He,p3n)186Re, 186W(4He,pn)188Re, 186W(4He,p)189Re Reaction Cross Sections By 4He Irradiation of 186W TARGET

Atomic Energy - The cross sections of the reactions 186W(4He, p3n)186Re, 186W(4He, pn)188Re, and 186W(4He, p)189Re were measured by the activation method in the energy range of 4He nuclei...     

Excitation functions of proton induced nuclear reactions on W up to 40 MeV

We measured the excitation functions for the production of the ^{181,182m,182g,183,184g,186}Re radioisotopes from proton bombardment of natural tungsten by using a stacked-foil activation technique in the energy range from threshold energy to 40 MeV at the MC50 cyclotron of the Korea Institute of Radiological and Medical Science. The results were compared with the earlier reported experimental data and the model calculations using codes TALYS and ALICE-IPPE. The present values are in good agreement with some of the previously reported literature. The integral yields for thick targets were also deduced from the measured excitation functions of the produced radioisotopes. The deduced yield values were compared with the available directly measured thick target yield, and found acceptable agreement. The investigated radioisotope ¹⁸⁶Re has remarkable applications in the field of nuclear medicine, whereas the data of ^183,184gRe have potential applications in thin layer activation analysis.     

Nanographene oxide labeling with 188Re

Nanographene oxide (NGO) is currently being explored for various biomedical applications. However, little information is known about its biological behaviors in vitro and in vivo. For further studying its pharmacokinetics and related biological behaviors in living systems, an effective and convenient tracing method is particularly demanded. In this work, NGO was labeled with radionuclide 188Re (188Re-NGO). To obtain high labeling yield and purity, a number of labeling conditions, including concentration of SnCl2 and ascorbic acid, reaction time and temperature, and pH were optimized, and stability of the 188Re-NGO in vitro and in vivo was evaluated. The results showed that NGO could be effectively labeled with high yield. The purified 188Re-NGO showed high stability in vitro and in vivo. A pretest of NGO biodistribution with single photon emission computed tomography showed that the 188Re-NGO was rapidly taken by organs such as lungs, liver, and spleen. The biodistribution of 188Re-NGO differs significantly from the free radionuclide, indicating that the labeling procedure is highly suitable for investigating its biological behavior in living systems.