Progress of photonuclear cross sections for medical radioisotope production at the SLEGS energy domain

Photonuclear reactions using a laser Compton scattering(LCS)gamma source provide a new method for producing radioisotopes for medical applications.Compared with the conventional method,this method has the advantages of a high specific activity and less heat.Initiated by the Shanghai Laser Electron Gamma Source(SLEGS),we conducted a survey of potential photonuclear reactions,(γ,n),(γ,p),and(γ,γ')whose cross sections can be measured at SLEGS by summarising the experimental progress.In general,the data are rare and occasionally inconsistent.Therefore,theoretical calculations are often used to evaluate the production of medical radioisotopes.Subsequently,we verified the model uncertainties of the widely used reaction code TALYS-1.96,using the experimental data of the^(100)Mo(γ,n)^(99)Mo,^(65)Cu(γ,n)^(64)Cu,and^(68)Zn(γ,p)^(67)Cu reactions.

Man-made plutonium radioisotopes in the salt lakes of the Crimean peninsula

Investigations of ^(239+240)Pu and ^(238)Pu in the surface layer(0–5 cm) of bottom sediment in the Crimean 10 salt lakes from 4 geographical groups were carried out for the first time. The ^(239+240)Pu varied widely between regional geographical groups of lakes as well as within groups too and ranged from 11±4 to 451±43 mBq^(239+240)Pu/kg. The highest levels of ^(239+240)Pu—419±27, 443±24 and 451±43 mBq/kg were observed in the Yevpatoriya(Lake Kyzyl-Yar), the Tarkhankut(Dzharylhach) and the Kerch group(Tobechik), respectively. The lowest values of ^(239+240)Pu were identified in three lakes of the Perekop group and were 20±12, 24±6 and 48±6 mBq/kg. In all lakes ^(238)Pu was an order of magnitude lower than 239+240 Pu and varied from 4.8±2.6 to 30.7±5.5 mBq/kg. The ^(238)Pu activity was decay-corrected to 1986. The characteristic ratio of the ^(238)Pu/239+240 Pu activities in the sediment and percentage of the Chernobyl-derived Pu was calculated. The largest percentages of the Chernobyl-derived Pu were observed in the Evpatoriya group(Lake SasykSivash)—16.2%±8.26%, the Tarkhankut group(Dzharylhach)—8.4%±2.10% and the Kerch group(Aktash)—10.5%±5.56%. The study of the depth distribution of plutonium in the Lake Kyzyl-Yar bottom sediment core(0–25 cm) was fulfilled. It was shown that 239+240 Pu was high enough in all studied layers of bottom sediment, but the highest activity ratio ^(238)Pu/239+240 Pu(0.062±0.020) was found in the deepest layer of 15–20.5 cm and the percentage of Chernobyl-derived Pu was estimated at 6.8%±2.85% in this layer.

Innovative Use of Light-Weight Radioisotopes in Therapeutics and the Engineering of Light-Power Generators

Light weight radioisotope (LWR) 89Sr and 90Sr could be obtained from used rods in fission atomic plants. The economics of the disposal of nuclear bars indicate the convenience to develop added value applications. The difference in t1/2 allows 89Sr to deliver its energy at a rate 200 times higher than 90Sr. A large emission number of low penetrating power particles in a short time characterize 89Sr, which allows that these highly radioactive LWR involves a rather limited danger. Chemical similitude of calcium and strontium uptake has led to the use of 89Sr in treatment of bone cancer metastasis. 89Sr damages animal tissues because ionize water, but penetrates through the skin about: 5 to 8 mm. Hence, to obtain it in insoluble form, like obtaining 89Sr silicate, could make possible its wider use. Purifying 89Sr from contaminant 90Sr allows that after one year do not leave any contamination. LWR could be covered with scintillators substances, which by subtracting kinetic energy from beta-radiation, emit light and function as a major source of shielding. This treatment engineers Radioisotope Light Generators (RLG). Their light could activate photovoltaic cells (PV), which could lead to nano-devices without moving parts RLG-PV.

Simulating the Production of Medical Radioisotopes in a Fast Thorium-Cycle ADS with SERPENT

Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.

Model-based cross section calculations on production of 43,34Sc,45Ti, 51Cr, 54Mn, and 55Fe radioisotopes

A cross section database on excitation functions of reactions produced by charged particles is essential for many areas of nuclear research. Particularly, accurate knowledge on nuclear cross sections for the cyclotron production of radioisotopes is very important for nuclear medicine. In the present paper, the cross section calculations for the production of^(43),^(34)Sc,^(45)Ti,^(51)Cr,^(54)Mn, and^(55) Fe radioisotopes were carried out by the use of ALICE/ASH code using the Fermi gas model, Kataria Ramamurthy Fermi gas model, and superfluid nuclear model for nuclear level density. Thereby, these model calculations were compared with the available measured data.

Evaluation of Excitation Functions of Reactions Used in Production of Some Medical Radioisotopes

In this work, reaction cross-sections were calculated and Excitation Functions were evaluated for productions of 208Bi, 212,211,210At, 211,210Po isotopes using EXIFON code in the energy range from 0 MeV to 30 MeV. The code is based on an analytical model for statistical multistep direct and multistep compound reactions (SMD/SMC model). This work also investigates the shell structure effect on the reaction cross-section, the results obtained show that the cross-sections of (a, na) reaction for both with shell correction and without shell correction are zeros at energies range considered, this shows that the energy of the incident particle is below the threshold of this reaction due to the present of coulomb repulsive force between the projectile and target nucleus.

Radioisotopes and Analytical Chemistry

When Periodic Chart of elements is consulted to find natural radioisotopes, one firstly finds tritium, followed by 10Be, 14C, 50V and many others. Before Bi, 12 cosmogenic radioisotopes are listed. They are those continuously produced by nuclear reactions among light elements present in earthly atmosphere and radiations coming from the outside space. Eighteen additional primordial radioisotopes are listed. They were created at the same time that the non-radioactive isotopes composing the 92 natural elements in the periodic table. From Bi on, every isotope is radioactive, up to U. Then follow the artificial elements produced by laboratory nuclear reactions from Np to element with atomic number 118. In this way, from 118 known elements, 64 are radioactive, which amount 55% of all those units forming the chemical compounds. Therefore, the complete understanding of radioactivity should be a suitable tool to advance our knowledge of Universe, and consequent applications to get better living conditions. So, this paper deals with radioisotopes as suitable instruments for chemical analysis.

Identification of Medical and Industrial Used Radioisotopes in Mining Sites of Nasarawa,Nasarawa State,Nigeria

This research intends to unveil the presence of radioisotopes in the soil of some mining sites in Nasarawa of Nasarawa state using thermos-scientific interceptor(IdentiFINDER).The work aimed at detecting the presence,types and trust level of radioisotopes.The result showed that,103Pd and 125I were found in 57%of the total points and the percentage abundance of the detector reached 50-65%indicating that,those radioisotopes are likely found in the area,109Cd was found in 15%of the total areas.The percentage abundance of the detector for 109Cd shows 50%indicating that,those radioisotopes are likely to be found in the area,241Am was found in 7%of the total areas.The percentage abundance of the detector for 241Am shows 81%indicating that,those radioisotopes are likely found in the area,235U was found in 7%of the total points.The percentage abundance of the detector for 235U reaches 57%indicating that,those radioisotopes are likely found in the area,75Se was found in 7%of the total points.The percentage abundance of the detector for 75Se was in abundance up to 57%indicating that,those radioisotopes are likely gotten in the area and 57Co was gotten in 7%of the total areas.The percentage abundance of the detector for 57Co was 54%indicating that,those radioisotopes are likely to be gotten in the area.Based on this high percentage abundance of the detector for these radioisotopes,they can be harnessed and applied appropriately in medicine and industry.

Facile preparation of^(177)Lu-microspheres for hepatocellular carcinoma radioisotope therapy

As one of the most common cancers in the world,hepatocellular carcinoma(HCC)has become a major threat to human health.Radioembolization is a first-line option for the treatment of HCC,especially when other conventional treatments fail or there exist some relative contraindications.Herein,we developed a facile and efficient method for preparing ^(177)Lu-microspheres potentially useful for precise radioembolization therapy of HCC.The radiolabeling efficiency of ^(177)Lu-microspheres was as high as 96.8%±0.5%,and the radiolabeling process did not alter the morphology of the mother microspheres.The SPECT/CT studies enabled by the unique emissions of ^(177)Lu suggested that almost no ^(177)Lu ion loaded by the microspheres was released over more than 32 d in vivo,which led to remarkable inhibition effect on the growth of HepG2 tumors subcutaneously transplanted in mice.The current approach may thus offer promising ^(177)Lu-microspheres for clinical radioembolization of HCC.

Fission gas released from molten salt reactor fuel:the case of noble gas short life radioisotopes for radiopharmaceutical application

The present study explores the potential of fission gas(Kr and Xe short life radioisotopes)released from a molten salt reactor,the separation of these noble gases using specific absorbents under well fixed conditions and the utilisation of these radioisotopes for radio-diagnostics.During operation,a molten salt reactor produces noble gas radioisotopes that bubble out from the liquid fuel and that can be sampled and treated for radiopharmaceutical applications including as tols for diagnostics using radioisotopes and/or potentially in radiotherapy for specific Vviral diseases usingβ^(-)emtters.Among them^(133)Xe is currenty used fr ung diagnostics thanks to its 132.9 keγ.The use of^(85)Kr for diagnostics is also examined.Its 514 keγcpuld be used for scintigraphy,However^(133)Xe utilisation imply also itsβ^(-)(E_(mean)≈100 kev)whose mean fre pathway of 100 nm in biological tissue or in wateris much smalier than the mean pathway of the^(95)Krβ^(-).Emphasis is placed on^(133)Xe because of its potential dual ability of imag ing and as a suggested therapeutic tool of viral lung diseases.

Accurate Formulae for the Cross-Section Data for the Radio-Halogen I-123 from Cyclotron Production

123I is the most widely used cyclotron-produced radio-halogen in medical research. In this paper, excitation function formulae for the nuclear reactions of 123I production are introduced. 124Te (p, 2n)123I and 127I (p, 5n)123Xe → 123I nuclear reactions have been studied as a function of the energy of the neutrons. Both two formulae were created using the least squares regression of the experimental cross sections data, which were obtained from the Experimental Nuclear Reaction Data EXFOR Database version of 2023. The proposed formulae were evaluated using two statistical indicators for goodness-of-fit. High agreement was observed between the empirical and experimental results for both nuclear processes.

乳糖化修饰纳米基因载体的肝靶向性研究(英文)

Objective:To compare the targeting effects of lactosarninated alginate(AlgNP)、polyethylene glycol - coated hydroxyapatite- poly- L- lysine nanoparticles (PLL- PCHNP)and relative nonlactosaminated ones load ed with exogenous gene on liver via peripheral intravenous route. Methods:Preparation of AlgNP based on control of gelification phenomenon of algiante by calcium ions and HA- PLLNP with collosol - gel method, both further modified with lactosaminated - poly- L - lysine synthesized by reductive lactosamination . We used pEGFPCl as the reporter gene to establish receptor- mediated and positive liver targeting nanoparticles- gene model. The potential of adsorbing DNA on nanoparticles was analysed by electrophoresis and spectrophotometer. Then different complexes were transferred into the rat's body by peripheral intravenous route and their targeting characteristics in liver were investigated by using radioisotope tracing assay. Results: PCHNP presented as needle - like particles with a diameter of 20nm by TEM and could be effectively combined with PLL. The diameter of AlgNP was 280nm. Agarpse gel electrophoresis showed both nanoparticles could effectively combine with DNA and the optimal proportion of PLLPCHNP and DNA was 30:1 (w/w); DNA mixed ratio of AlgPLL was 68.3 % by spectrophotometer. The radioactivities in liver for the two lactosaminated nanoparticles were higher than the nonlactosaminated ones. No statistic difference between AlgNP and AlgLacNP could be found . Conclusions: Lactosaminated naroparticles can target to liver more effectively by peripheral intravenous route than nonlactosaminated ones, which is closely concerned with the characteritics of the nanopartide complex.

Serial stimulated thyroglobulin measurements are more specific for detecting distant metastatic differentiated thyroid cancer before radioiodine therapy

Objective: Preablative stimulated thyroglobulin(ps-Tg) has the potential to be used in identifying distant metastatic differentiated thyroid carcinoma(DM-DTC), but its single level can be affected by remnant thyroid tissue and thyrotropin(TSH). The objective of this retrospective study was to evaluate the value of serial ps-Tg measurements in identifying DM-DTC specifically.Methods: A total of 317 DTC patients with serial measurements of ps-Tg, TSH and anti-Tg antibody were divided into M1(n=72) and M0(n=245) according to the presence of distant metastasis(DM) or not. The initial psTg measurement, with a corresponding TSH exceeding 30 μIU/m L, was marked as Tg1, and ps-Tg measured right before radioactive iodine(RAI) therapy was defined as Tg2, with a median interval of 8 days. ΔTg denotes Tg2–Tg1, and ΔTSH denotes TSH2–TSH1. Tg1, Tg2, ΔTg, and ΔTg/ΔTSH were tested for efficacy in identifying DM-DTC using receiver operating characteristic(ROC) curve analysis, and further compared with chest computed tomography(CT) and posttreatment whole-body RAI scan(Rx WBS).Results: Compared with single ps-Tg measurement(Tg1 or Tg2), both ΔTg and ΔTg/ΔTSH were more narrowly distributed around zero in the M0 group, which made their distribution in the M1 group more distinguished in a relatively dispersed way. ΔTg/ΔTSH manifested a higher accuracy(88.64%) and specificity(90.20%) in identifying DM-DTC than Tg1 or Tg2 measurements, with a much higher specificity than chest CT(90.20% vs. 66.00%) and a much higher sensitivity than Rx WBS(83.33% vs. 61.11%).Conclusions: Serial ps-Tg measurements even over as short an interval as 8 days hold incremental value in identifying DM-DTC. ΔTg/ΔTSH is a specific early biochemical marker for DM-DTC.

Treatment of portal vein tumor thrombus using ^(125)Iodine seed implantation brachytherapy

We reported two cases of liver metastasis with portal vein tumor thrombus that developed after liver transplantation for hepato cellular carcinoma (HCC). Both the patients were women aged 43 and 55 years, who had liver metastasis and portal vein tumor thrombus formation after liver transplantations for HCC. For the treatment of portal vein tumor thrombus, 125I seeds were implanted into the hepatic tissue under the guidance of preoperative computed tomography (CT) images with a total radiation dose of 130 Gy. Enhanced spiral CT scan was performed for evaluation of the liver at 12 and 16 wk after treatment. Thereafter, upper abdominal CT examination was performed every 2-3 mo. No severe complications associated with the 125I seeds were seen in these two patients. The upper abdominal CT images (obtained after 3 and 4 mo of treatment) showed that the thrombosis reactions were complete reaction and restoration of the patency of the partially obstructed portal vein with partial obstruction. In the case with complete obstruction of the portal vein, the thrombosis was resolved completely, but blood flow could not be restored. After this treatment, one of the patients is stillalive, while the other died within 6 mo after the treatment due to lung metastasis complicated with lung infection, leading to respiratory failure.

Baculovirus vector-mediated transfer of NIS gene into colon tumor cells for radionuclide therapy

AIM:To investigate the feasibility of radionuclide therapy of colon tumor cells by baculovirus vector-mediated transfer of the sodium/iodide symporter(NIS) gene.METHODS:A recombinant baculovirus plasmid carrying the NIS gene was constructed,and the viruses(BacNIS) were prepared using the Bac-to-Bac system.The infection efficiency in the colon cancer cell line SW1116 of a green fluorescent protein(GFP) expressing baculovirus(Bac-GFP) at different multiplicities of infection(MOI) with various concentrations of sodium butyrate was determined by flow cytometry.An in vitro cytotoxicity assay was also conducted after infection of SW1116 cells with Bac-NIS.Iodine uptake of Bac-NIS infected SW1116 cells and inhibition of this uptake by sodium perchlorate was examined,and the effect of Bac-NISmediated 131 I in killing tumor cells was evaluated by cell colony formation tests.RESULTS:Infection and transgene expression in SW1116with Bac-GFP were significantly enhanced by sodium butyrate,as up to 72% of SW1116 cells were infected with the virus at MOI of 400 and sodium butyrate at 0.5 mmol/L.No obvious cytotoxicity was observed under these conditions.Infection of SW1116 with Bac-NIS allowed uptake of 131 I in these tumor cells,which could be inhibited by sodium perchlorate.The viability of SW1116 cells infected with Bac-NIS was significantly lower than with Bac-GFP,suggesting that NIS gene-mediated 131 I uptake could specifically kill tumor cells.CONCLUSION:Baculovirus vector-mediated NIS gene therapy is a potential approach for treatment of colon cancer.

Exploratory study of betavoltaic battery using ZnO as the energy converting material

Third-generation-semiconductor zinc oxide is utilized as an energy converting material in a betavoltaic battery, where 0.06 Ci^(63) Ni and 8 Ci^(147) Pm are used as the beta sources. Based on a Monte Carlo simulation, the full scales of the devices are derived as 17 and 118 lm,respectively, for both sources. The influences of semiconductor doping concentrations on the electrical properties of the devices are analyzed. For a typical doping concentration N_A= 10^(17) cm^(-3), N_D= 10^(16) cm^(-3), the conversion efficiencies are 7.177% and 1.658%, respectively, using63 Ni and147 Pm sources. The calculation results of energy deposition in materials for the two sources show that the doping concentrations drop to 1 × 10^(13)–5×10^(14) cm^(-3) and 1 × 10^(12)–5×10^(13), and accordingly, the energy conversion efficiencies rise to 14.212% and 18.359%, respectively.

Investigation of production of medical ^(82)Sr and ^(68)Ge for ^(82)Sr/^(82)Rb and ^(68)Ge/^(68)Ga generators via proton accelerator

How to operate^(82)Sr/^(82)Rb and ^(68)Ge/^(68)Ga generators used in the positron emission tomography scan process is explained, and the importance of ^(82)Sr and ^(68)Ge radionuclides for these generators is revealed. To produce medical ^(82)Sr and ^(68)Ge by means of a proton accelerator in an irradiation time of 24 h, a proton beam current of250 l A, and an energy range E_(proton)= 100 →5 MeV, the cross sections and the neutron emission spectrum curves of(p,xn) reaction processes on Rb-85, Ga-69 and Ga-71 targets were calculated, and the activities and yields of the product were simulated for the reaction processes. Additionally, the integral yields of the reaction processes were determined via the calculated cross-sectional curves and the mass stopping power obtained from the X-PMSP program. Furthermore, based on the obtained results, the appropriate reaction processes for the production of ^(82)Sr and ^(68)Ge isotopes on Rb-85, Ga-69, and Ga-71 targets are discussed.

Tumour Localization of A Mitomycin C-Monoclonal Antibody MGb_2 Conjugate in Nude Mice with Human Gastric Carcinoma Xenografts

MGb2 is a monoclonal antibody againstgastric cancer.It can be well localized in thetumour tissue and has been successfully used inthe radioimmunoimaging in the patients withgastric cancer.The conjugate of MGb2 withchemotherapeutic drug mitomycin C（MMC）al-so shows highly selective cytotoxic effect uponhuman gastric cancer cells in vitro.

INVESTIGATIONS OF NATURAL AND ARTIFICIAL RADIOACTIVE ISOTOPES IN SEAWATER AND SEDIMENTS IN THE YELLOW SEA AND ADJACENT SOUTHEAST AREA

Investigations of natural and artificial radioisotopes including 90Sr,137Cs, gross B and U carried out in the Yellow Sea and adjacent southeast area in 1963. 1964, 1975 and 1978 showed that radioactive pollution by 90Sr and 137Cs from atmospheric fallout had gradually decreased with time due to the cessation of atmospheric nuclear weapons tests in the 70s. The distributions of natural and artificial radioactive isotopes (U, Ra, Th. 40K and 137Cs) in sediments southwest of Jizhou Island were uniform. The more uniform may be related to the soluble species of U[Uo2(CO3)4] in the seawater.The high value of Th at stations 3 and 6 was related to the sandy clay sediment; the low value at station 8 was related to sandy sediment. The content of 137Cs in the eddy area being less than about half of that in the China inshore area showed that the source of Cs may be insufficient orthat the conditions for enriching " Cs in the circulation eddy area were not favorable.

Influence of four kinds of polysaccharides on the induction of lymphokine-activated killer cells in vitro

Effects of Lycium barbarum polysaccharide（LBP）,Astragalus polysaccharide（APS）,polysaccharide of Acanthopanax senticosus（PAS）and polysaccharide of bacteriallipopolysaccharide（PS）on the induction of lymphokine-activated killer（LAK）cells fromC57BL/6 murine splenocytes were studied using [125I]UdR release assay.The fourpolysaccharides alone were shown to induce no cytotoxicity.When combined with humanrecombination interleukin-2（rlL-2）,they augmented LAK cell activities in adose-dependent manner,most markedly at 0.01～0.1 mg·ml-1for LBP,0.01 mg·ml-1 forAPS and PAS,and 0.01 μg·ml-1 for PS.They increased LAK cell activity in a shortrange of rIL-2 concentrations(250～1000U·ml-1).They were shown to inhibit LAK cellactivity when used beyond the suitable dosage.