Feasibility study of the photonuclear reaction cross section of medical radioisotopes using a laser Compton scattering gamma source

In recent years,the gap between the supply and demand of medical radioisotopes has increased,necessitating new methods for producing medical radioisotopes.Photonuclear reactions based on gamma sources have unique advantages in terms of producing high specific activity and innovative medical radioisotopes.However,the lack of experimental data on reaction cross sections for photonuclear reactions of medical radioisotopes of interest has severely limited the development and production of photonuclear transmutation medical radioisotopes.In this study,the entire process of the generation,decay,and measurement of medical radioisotopes was simulated using online gamma activation and offline gamma measurements combined with a shielding gamma-ray spectrometer.Based on a quasi-monochromatic gamma beam from the Shanghai Laser Electron Gamma Source(SLEGS),the feasibility of this measurement of production cross section for surveyed medi-cal radioisotopes was simulated,and specific solutions for measuring medical radioisotopes with ultra-low production cross sections were provided.The feasibility of this method for high-precision measurements of the reaction cross section of medical radioisotopes was demonstrated.

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.

The progress of radioisotope technology and application in China

The inception of radioisotope and its application in China are introduced. The research,development, production, application progress and the future development prospect of radioisotope and its products are described.

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.

Effects of extravascular trestle model coated phosphorus radioisotope on intimal hyperplasia in autologous vein grafts

Objective: To design an extravascular trestle model coated phosphorus-32, an isotope radiating beta rays, and investigate its effects on intimal hyperplasia of autologous vein grafts. Methods: ETA cDNA was used as a gene probe specific to vascular SMCs on the basis of in situ hybridization. The femoral veins were transplanted reversely into colateral femoral arteries in rabbits, and the animals were divided into control, chemical agents and phosphorus-32 groups. The morphometry was applied to calculate the ETA cDNA expression and intimal thickness. Spearman correlation method was utilized to investigate their relationship. Results: Intimal thickness in grafts of phosphorus-32 group was markedly reduced. Additionally, intimal ETA gene expression was also decreased in beta rays group. The values increased at a slower rate significantly different from that of control and aspirin groups (P<0.01). The correlation of ETA cDNA expression and intimal thickness exhibited a strongly positive relation. Conclusion: Beta rays in extravascular model could remarkably inhibit intimal thickening and SMC proliferation. The correlation is an indirect evidence indicating that intimal hyperplasia composed of SMCs proliferation. It suggests that ETA cDNA expression could be a quantitative estimation of vascular SMC because of its specifics.

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.

A half-century of radioisotope neutron sources in China

Near 50 years history of the development of radioisotope neutron sources in China is briefly reviewed.The structure design,preparing technology and production status of routine neutron sources including 210Po-Be sources,210Po mock fission sources,241Am-Be sources,238Pu-Be sources,252Cf spontaneous fission sources and other special-shape neutron sources are summarized.In addition,the prospects of development on radioisotope neutron source in China are predicted from the needs of nuclear power construction,oil well-logging,neutron moisture gauge and neutron brachytherapy.

Strategic Planning as a Competitive Advantage by Using the BSC as a Management Tool： A Case Study in Application of Radioisotope Technology at IPEN

Strategic planning is one of the most important management tools for organizational decision making. The nuclear area represents a segment of energy production used by many countries in America, Europe and Asia. It is known that in the future nuclear energy can be a major exit to the global energy crisis. The aim of this research was to use the BSC （Balanced Scorecard） as a strategic tool for decision making in a teaching and research institution of the nuclear area--IPEN （Nuclear and Energy Research Institute）, located in the city of Sao Paulo, which belongs to the CNEN （National Nuclear Energy Commission） in Brazil. The methodology used in this academic doctoral study was a case study, which considered the period of research from December 2012 to December 2015. The main results expected from this case study are： the improvement of information flow, the view, the increased visibility of an organization providing education and especially research in relation to published works, increased interaction among IPEN and the main global research institutes and centers, increasing academic production of technical articles, indicator improvement, improving the monitoring of management actions, among others. Given the expected results one can conclude that this study will be of great value to the IPEN and also for the Brazilian energy sector, as it will allow and contribute to the dissemination and demystification of nuclear power as an energy source of mankind, its peaceful applications and for the management activity of knowledge and innovation production in the nuclear area of IPEN.

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.

Development of Kabila rocket: A radioisotope heated thermionic plasma rocket engine

A new type of plasma rocket engine, the Kabila rocket, using a radioisotope heated thermionic heating chamber instead of a conventional combustion chamber or catalyst bed is intro- duced and it achieves specific impulses similar to the ones of conventional solid and bipropellant rockets. Curium-244 is chosen as a radioisotope heat source and a thermal reductive layer is also used to obtain precise thermionic emissions. The self-sufficiency principle is applied by simultane- ously heating up the emitting material with the radioisotope decay heat and by powering the differ- ent valves of the plasma rocket engine with the same radioisotope decay heat using a radioisotope thermoelectric generator. This rocket engine is then benchmarked against a 1 N hydrazine thruster configuration operated on one of the Pleiades-HR-1 constellation spacecraft. A maximal specific impulse and power saving of respectively 529 s and 32% are achieved with helium as propellant. Its advantages are its power saving capability, high specific impulses and simultaneous ease of storage and restart. It can however be extremely voluminous and potentially hazardous. The Kabila rocket is found to bring great benefits to the existing spacecraft and further research should optimize its geometric characteristics and investigate the physical principals of its operation.

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.

Localized Effects of Mechanical Wounding and Exogenous Jasmonic Acid on the Induction of Secondary Laticifer Differentiation in Relation to the Distribution of Jasmonic Acid in Hevea brasiliensis

The relationship between the effect of exogenous jasmonic acid (JA) on the induction of secondary laticifer differentiation and the distribution of JA in the seedling of Hevea brasiliensis Mull. Arg. was investigated with the aid of experimental morphological and radioisotope technique. Most radioactivity of H-3-JA sustained in treated site within one hour while no radioactivity was detected in new shoot and the radioactivity in upper leaf was much less than that in the parts below the treated site, suggesting that JA was mainly transported downwards in the shoot of H brasiliensis. Mechanical wounding hindered the entrance of exogenous JA remarkably while held back the entered JA to the regions around wounded site. The effect of exogenous JA and mechanical wounding on the induction of the secondary laticifer differentiation was limited to treated site where high level of JA was expected. Mechanical wounding reduced the effect of exogenous JA on the differentiation of secondary laticifer, which could be ascribed to the hindrance of mechanical wounding to the entrance of exogenous JA. It was concluded from the combined data that a high accumulation of JA was required for inducing the secondary laticifer differentiation in H. brasiliensis.

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.

Clinical observation of 125 I labeled anti alpha fetoprotein antibody radioimmunotherapy in hepatocellular carcinoma *

AIM To observe the therapeutic effects and toxic side reactions of 125 I labeled hourse anti human AFP polyclonal antibodies in immuno targeting therapy against hepatocellular carcinoma (HCC).