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  1. Fulltext Preparation and In Vitro Evaluation of Neutron-Activated, Theranostic Samarium-153-Labeled Microspheres for Transarterial Radioembolization of Hepatocellular Carcinoma and Liver Metastasis
    Wong YH, Tan HY, Kasbollah A, Abdullah BJJ, Yeong CH
    Pharmaceutics, 2019 Nov 12;11(11).
    PMID: 31718079 DOI: 10.3390/pharmaceutics11110596
    INTRODUCTION: Transarterial radioembolization (TARE) has been proven as an effective treatment for unresectable liver tumor. In this study, neutron activated, 153Sm-labeled microspheres were developed as an alternative to 90Y-labeled microspheres for hepatic radioembolization. 153Sm has a theranostic advantage as it emits both therapeutic beta and diagnostic gamma radiations simultaneously, in comparison to the pure beta emitter, 90Y.

    METHODS: Negatively charged acrylic microspheres were labeled with 152Sm ions through electrostatic interactions. In another formulation, the Sm-labeled microsphere was treated with sodium carbonate solution to form the insoluble 152Sm carbonate (152SmC) salt within the porous structures of the microspheres. Both formulations were neutron-activated in a research reactor. Physicochemical characterization, gamma spectrometry, and radiolabel stability tests were carried out to study the performance and stability of the microspheres.

    RESULTS: The Sm- and SmC-labeled microspheres remained spherical and smooth, with a mean size of 35 µm before and after neutron activation. Fourier transform infrared (FTIR) spectroscopy indicated that the functional groups of the microspheres remained unaffected after neutron activation. The 153Sm- and 153SmC-labeled microspheres achieved activity of 2.53 ± 0.08 and 2.40 ± 0.13 GBq·g-1, respectively, immediate after 6 h neutron activation in the neutron flux of 2.0 × 1012 n·cm-2·s-1. Energy-dispersive X-ray (EDX) and gamma spectrometry showed that no elemental and radioactive impurities were present in the microspheres after neutron activation. The retention efficiency of 153Sm in the 153SmC-labeled microspheres was excellent (~99% in distilled water and saline; ~97% in human blood plasma), which was higher than the 153Sm-labeled microspheres (~95% and ~85%, respectively).

    CONCLUSION: 153SmC-labeled microspheres have demonstrated excellent properties for potential application as theranostic agents for hepatic radioembolization.

    Matched MeSH terms: Neutrons
  2. Impact of molecular structure, headgroup and alkyl chain geometry, on the adsorption of the anionic ester sulfonate surfactants at the air-solution interface, in the presence and absence of electrolyte
    Wang Z, Li P, Ma K, Chen Y, Campana M, Penfold J, et al.
    J Colloid Interface Sci, 2019 May 15;544:293-302.
    PMID: 30861434 DOI: 10.1016/j.jcis.2019.03.011
    The transition from monolayer to multilayer adsorption at the air-water interface in the presence of multivalent counterions has been demonstrated for a limited range of anionic surfactants which exhibit increased tolerance to precipitation in the presence of multivalent counterions. Understanding the role of molecular structure in determining the transition to surface ordering is an important aspect of the phenomenon. The focus of the paper is on the alkyl ester sulfonate, AES, surfactants; a promising group of anionic surfactants, with the potential for improved performance and biocompatibility. Neutron reflectivity measurements were made in aqueous solution and in the presence of NaCl, CaCl2, MgCl2 and AlCl3, for a range of alkyl ester sulfonate surfactants, in which the headgroup and alkyl chain geometries were manipulated. In the regions of monolayer adsorption changing the AES headgroup and alkyl chain geometries results in an increased saturation adsorption and in a more gradual decrease in the adsorption at low concentrations, consistent with a greater adsorption efficiency. Changing the AES headgroup and alkyl chain geometries also results in changes in the transition from monolayer adsorption to more ordered surface structures with the addition of AlCl3 and mixed multivalent electrolytes. A more limited surface layering is observed for the ethyl ester sulfonate, EES, with a C14 alkyl chain. Replacing the C14 alkyl chain with a C18 isostearic chain results in only monolayer adsorption. The results demonstrate the role and importance of the surfactant molecular structure in determining the nature of the surface adsorption in the presence of different electrolytes, and in the tendency to form extended surface multilayer structures.
    Matched MeSH terms: Neutrons
  3. The thermoluminescence response of doped SiO2 optical fibres subjected to fast neutrons
    Hashim S, Bradley DA, Saripan MI, Ramli AT, Wagiran H
    Appl Radiat Isot, 2010 Apr-May;68(4-5):700-3.
    PMID: 19892557 DOI: 10.1016/j.apradiso.2009.10.027
    This paper describes a preliminary study of the thermoluminescence (TL) response of doped SiO(2) optical fibres subjected to (241)AmBe neutron irradiation. The TL materials, which comprise Al- and Ge-doped silica fibres, were exposed in close contact with the (241)AmBe source to obtain fast neutron interactions through use of measurements obtained with and without a Cd filter (the filter being made to entirely enclose the fibres). The neutron irradiations were performed for exposure times of 1-, 2-, 3-, 5- and 7-days in a neutron tank filled with water. In this study, use was also made of the Monte Carlo N-particle (MCNP) code version 5 (V5) to simulate the neutron irradiations experiment. It was found that the commercially available Ge-doped and Al-doped optical fibres show a linear dose response subjected to fast neutrons from (241)AmBe source up to seven days of irradiations. The simulation performed using MCNP5 also exhibits a similar pattern, albeit differing in sensitivity. The TL response of Ge-doped fibre is markedly greater than that of the Al-doped fibre, the total absorption cross section for Ge in both the fast and thermal neutrons region being some ten times greater than that of Al.
    Matched MeSH terms: Neutrons
  4. Fulltext Estimation of (99)Mo production rates from natural molybdenum in research reactors
    Blaauw M, Ridikas D, Baytelesov S, Salas PS, Chakrova Y, Eun-Ha C, et al.
    J Radioanal Nucl Chem, 2017;311(1):409-418.
    PMID: 28111485 DOI: 10.1007/s10967-016-5036-6
    Molybdenum-99 is one of the most important radionuclides for medical diagnostics. In 2015, the International Atomic Energy Agency organized a round-robin exercise where the participants measured and calculated specific saturation activities achievable for the (98)Mo(n,γ)(99)Mo reaction. This reaction is of interest as a means to locally, and on a small scale, produce (99)Mo from natural molybdenum. The current paper summarises a set of experimental results and reviews the methodology for calculating the corresponding saturation activities. Activation by epithermal neutrons and also epithermal neutron self-shielding are found to be of high importance in this case.
    Matched MeSH terms: Neutrons
  5. Fulltext Measurement in a bulky paper-recycling
    Norpaiza Mohamad Hasan, Noraini Haron, Mohamad, Glam Hadzir Patai, Ismail Mustapha, Syed Yusainee Syed Yahya
    Jurnal Sains Nuklear Malaysia, 2011;23(2):60-66.
    MyJurnal
    Paper recycling plants usually buy their raw material from suppliers. More than often, bulk used paper supplied to the plant contains some significant quantity of water in its internal voids. It may be included intentionally or unintentionally. The price of used paper depends on its weight, thus adding water will help to increase weight and consequently increase the price. In this way, plant owner who purchase the used paper suffers a significant of financial lost. The objectives of our experiment are to establish a calibration curve that correlate between the amount of neutron backscattered and water content, and finally to develop a correction factor that need to be introduced to the measured values of water content. A fast neutron source (Am-Be 241) and a portable backscattering neutron detector were used for water measurement. The experiments were carried out by measuring neutron backscattering from used paper that has been added with different amount of water. As a result, a neutron calibration curve that provides a correlation between neutron backscattering and water content was established.
    Matched MeSH terms: Fast Neutrons; Neutrons
  6. Industrial radiotracer application in flow rate measurement and flowmeter calibration using 99mTc and 198Au nanoparticles radioisotope
    Mohd Yunos MAS, Hussain SA, Sipaun SM
    Appl Radiat Isot, 2019 Jan;143:24-28.
    PMID: 30368049 DOI: 10.1016/j.apradiso.2018.10.008
    The flow rate or fluid velocity measurement is important to maintain fluid flow quality performance in the systems. This study focuses on determination of volumetric flow rate measurement and to calibrate the conventional flowmeter using industrial radiotracer approach in quadrilateral gas-liquid bubble column reactor. In this work, two different radioisotopes which emit γ-ray have been chosen as radioactive tracer which is 99mTc produced from 99Mo/99mTc radioisotope generator and 198Au nanoparticle form neutron activation at research nuclear reactor TRIGA Mark II. Both radioisotopes representing liquid and solid tracer purposely designed for tracing liquid flow. The peak to peak radiotracer method known as pulse velocity method was applied to determine the volumetric flow rate. The radiation signals were monitored using 4 unit NaI scintillation detectors located at 4 different points nearby the inlet and outlet of the quadrilateral bubble column reactor process stream. The water volume inside the bubble column reactor was fixed at 0.04 m3 and liquid flow rates in this reactor were specified on installed flowmeter at different reference value which is 4 lpm, 8 lpm, and 12 lpm, respectively. The experimental result shows very good linearity and repeatability by following the theoretical equations with less uncertainty in volumetric flow rate measurement. The obtained results also validated the effectiveness of the proposed method for the installed flowmeter calibration efficiency.
    Matched MeSH terms: Neutrons
  7. Fulltext Fabrication and characterisation of aluminium boron carbide composites for neutron shielding
    Yusof Abdullah, Mohd Reusmaazran Yusof, Nadira Kamarudin, Paulus, Wilfred Sylvester, Rusnah Mustaffa, Nurazila Mat Zali, et al.
    Jurnal Sains Nuklear Malaysia, 2012;24(1):71-80.
    MyJurnal
    Al/B4C composites with 0 wt.%, 5 wt.% and 10 wt.% of B4C were prepared by powder metallurgy and their properties were characterised successfully. Investigation of the effect of milling times (4, 8, 12, 16 hours) on microstructure, phase identification, hardness and neutron attenuation coefficient of composites has been studied. The results showed that hardness increased with increased of milling time, with maximum hardness obtained at 16 hours milling time. The increment is slower as the composition of B4C increased. The hardness of Al/10%B4C, Al/5%B4C and Al/0%B4C were 81.7, 78.7 and 61.2 HRB respectively. Morphology of scanning electron microscopy (SEM) showed that microstructures play important role in controlling the hardness. Meanwhile, x-ray diffraction (XRD) analysis showed the phases and crystalline present in composites with an indication that crystalline of the grain increased as the milling time increased. Neutron absorption of Al/10%B4C composites showed that this composite has the highest attenuation coefficient, thus indicating that it is the best composites for neutron shielding.
    Matched MeSH terms: Neutrons
  8. α-Sulfo alkyl ester surfactants: Impact of changing the alkyl chain length on the adsorption, mixing properties and response to electrolytes of the tetradecanoate
    Wang Z, Li P, Ma K, Chen Y, Yan Z, Penfold J, et al.
    J Colloid Interface Sci, 2021 Mar 15;586:876-890.
    PMID: 33309145 DOI: 10.1016/j.jcis.2020.10.122
    HYPOTHESIS: The α-sulfo alkyl ester, AES, surfactants are a class of anionic surfactants which have potential for improved sustainable performance in a range of applications, and an important feature is their enhanced tolerance to precipitation in the presence of multivalent counterions. It is proposed that their adsorption properties can be adjusted substantially by changing the length of the shorter alkyl chain, that of the alkanol group in the ester.

    EXPERIMENTS: Surface tension and neutron reflectivity have been used to investigate the variation in the adsorption properties with the shorter alkyl chain length (methyl, ethyl and propyl), the impact of NaCl on the adsorption, the tendency to form surface multilayer structures in the presence of AlCl3, and the effects of mixing the methyl ester sulfonate with the ethyl and propyl ester sulfonates on the adsorption.

    FINDINGS: The variations in the critical micelle concentration, CMC, the adsorption isotherms, the saturation adsorption values, and the impact of NaCl illustrate the subtle influence of varying the shorter alkyl chain length of the surfactant. The non-ideal mixing of pairs of AES surfactants with different alkanol group lengths of the ester show that the extent of the non-ideality changes as the difference in the alkanol length increases. The surface multilayer formation observed in the presence of AlCl3 varies in a complex manner with the length of the short chain and for mixtures of surfactants with different chains lengths.

    Matched MeSH terms: Neutrons
  9. Fulltext Characterization of alumina using small angle neutron scattering (sans)
    Megat Harun Al Rashid Megat Ahmad, Abdul Aziz Mohamed, Azmi Ibrahim, Che Seman Mahmood, Putra, Edy Giri Rachman, Muhammad Rawi Muhammad Zin, et al.
    Journal of Nuclear and Related Technologies, 2007;2005(1):19-23.
    MyJurnal
    Alumina powder was synthesized from an aluminum precursor and studied using small angle neutron scattering (SANS) technique and complemented with transmission electron microscope (TEM). XRD measurement confirmed that the alumina produced was of high purity and highly crystalline D-phase. SANS examination indicates the formation of mass fractals microstructures with fractal dimension of about 2.8 on the alumina powder.
    Matched MeSH terms: Neutrons
  10. The impact of electrolyte on the adsorption of the anionic surfactant methyl ester sulfonate at the air-solution interface: Surface multilayer formation
    Xu H, Thomas RK, Penfold J, Li PX, Ma K, Welbourne RJL, et al.
    J Colloid Interface Sci, 2018 Feb 15;512:231-238.
    PMID: 29073464 DOI: 10.1016/j.jcis.2017.10.064
    The methyl ester sulfonates represent a promising group of anionic surfactants which have the potential for improved performance and biocompatibility in a range of applications. Their solution properties, in particular their tolerance to hard water, suggests that surface ordering may occur in the presence of multi-valent counterion. Understanding their adsorption properties in a range of different circumstances is key to the exploitation of their potential. Neutron reflectivity and surface tension have been used to characterise the adsorption at the air-aqueous solution interface of the anionic surfactant sodium tetradecanoic 2-sulfo 1-methyl ester, C14MES, in the absence of electrolyte and in the presence of mono, di, and tri-valent counterions, Na+, Ca2+, and Al3+. In particular the emphasis has been on exploring the tendency to form layered structures at the interface. In the absence of electrolyte and in the presence of NaCl and CaCl2 and AlCl3 at low concentrations monolayer adsorption is observed, and the addition of electrolyte results in enhanced adsorption. In the presence of NaCl and CaCl2 only monolayer adsorption is observed. However at higher AlCl3 concentrations surface multilayer formation is observed, in which the number of bilayers at the surface depends upon the surfactant and AlCl3 concentrations.
    Matched MeSH terms: Neutrons
  11. Neutron-activated ¹⁵³Sm-ion-exchange resin as a tracer for gastrointestinal scintigraphy
    Yeong CH, Abdullah BJ, Ng KH, Chung LY, Goh KL, Sarji SA, et al.
    Nucl Med Commun, 2011 Dec;32(12):1256-60.
    PMID: 21934547 DOI: 10.1097/MNM.0b013e32834b3ac8
    Nuclear medicine techniques are well established for the investigation of gastrointestinal (GI) motility and transit. Ion-exchange resins radiolabelled with ⁹⁹mTc and ¹¹¹In are widely used as nonabsorbable radiopharmaceutical markers, with ¹¹¹In being preferred for whole-gut transit studies. This radionuclide, however, is not produced in many countries and may be expensive when obtained through international shipment. This study describes the use of neutron-activated ¹⁵³Sm-resin as an alternative tracer for use in GI scintigraphic investigation. A measure of 50 mg of stable samarium-152 chloride (¹⁵²SmCl₃) was incorporated into 100 mg of cation-exchange resin and irradiated in a neutron flux of 1 × 10¹³ cm⁻² s⁻¹ for 100 s to achieve an activity of 5 MBq after 66 h. Aliquots of ¹¹¹In-radiolabelled resin (5 MBq) were prepared for comparison of labelling and stability. Radiolabelling efficiencies were obtained by washing resin with distilled water, and the activity lost was measured. The radiolabelled resins were immersed in simulated gastric and intestinal fluid environments, and the retention of ¹⁵³Sm³⁺ and ¹¹¹In³⁺ was measured over a 24 h period. At 66 h after production, 91.15 ± 12.42% of ¹⁵³Sm was bound to the resin after washing in distilled water, whereas radiolabelling with ¹¹¹In achieved 99.96 ± 0.02% efficiency. Both radiolabelled resins demonstrated almost 100% stability in simulated intestinal fluid and >90% stability in artificial gastric juice over 24 h. The performance of neutron-activated ¹⁵³Sm-resin is similar to that of ¹¹¹In-resin and can be used as an alternative tracer for GI transit studies when In is not available.
    Matched MeSH terms: Neutrons
  12. Fulltext Neutron Activated Samarium-153 Microparticles for Transarterial Radioembolization of Liver Tumour with Post-Procedure Imaging Capabilities
    Hashikin NA, Yeong CH, Abdullah BJ, Ng KH, Chung LY, Dahalan R, et al.
    PLoS One, 2015;10(9):e0138106.
    PMID: 26382059 DOI: 10.1371/journal.pone.0138106
    Samarium-153 (153Sm) styrene divinylbenzene microparticles were developed as a surrogate for Yttrium-90 (90Y) microspheres in liver radioembolization therapy. Unlike the pure beta emitter 90Y, 153Sm possess both therapeutic beta and diagnostic gamma radiations, making it possible for post-procedure imaging following therapy.
    Matched MeSH terms: Neutrons
  13. Neutron-activated theranostic radionuclides for nuclear medicine
    Tan HY, Yeong CH, Wong YH, McKenzie M, Kasbollah A, Md Shah MN, et al.
    Nucl Med Biol, 2020 09 30;90-91:55-68.
    PMID: 33039974 DOI: 10.1016/j.nucmedbio.2020.09.005
    Theranostics in nuclear medicine refers to personalized patient management that involves targeted therapy and diagnostic imaging using a single or combination of radionuclide (s). The radionuclides emit both alpha (α) or beta (β-) particles and gamma (γ) rays which possess therapeutic and diagnostic capabilities, respectively. However, the production of these radionuclides often faces difficulties due to high cost, complexity of preparation methods and that the products are often sourced far from the healthcare facilities, hence losing activity due to radioactive decay during transportation. Subject to the availability of a nuclear reactor within an accessible distance from healthcare facilities, neutron activation is the most practical and cost-effective route to produce radionuclides suitable for theranostic purposes. Holmium-166 (166Ho), Lutetium-177 (177Lu), Rhenium-186 (186Re), Rhenium-188 (188Re) and Samarium-153 (153Sm) are some of the most promising neutron-activated radionuclides that are currently in clinical practice and undergoing clinical research for theranostic applications. The aim of this paper is to review the physical characteristics, current clinical applications and future prospects of these neutron activated radionuclides in theranostics. The production, physical properties, validated clinical applications and clinical studies for each neutron-activated radionuclide suitable for theranostic use in nuclear medicine are reviewed in this paper.
    Matched MeSH terms: Neutrons*
  14. Fulltext Cement-boron carbide concrete as radiation shielding material
    Yusof Abdullah, Mohd Reusmaazran Yusof, Azali Muhamad, Zaifol Samsu, Nurhaslinda Ee Abdullah
    Journal of Nuclear and Related Technologies, 2010;2010(2):74-79.
    MyJurnal
    Boron carbide (B4C) is a ceramic material which is effective to absorb thermal neutron due to wide neutron absorption cross section. In this work, B4C is added into concrete as fine aggregates to test the attenuation properties by getting the attenuation coefficient of the concrete/B4C. The samples of concrete/B4C were exposing to the thermal neutron radiation source (241-Americium-Berylium) at the dos rate of 29.08 mR/h. The result show that the attenuation coefficient of the sample with 20wt% B4C is 0.299cm -1 and the sample without B4C is 0.238cm -1 and hence, concrete/B4C is suitable as a shield for thermal neutron radiation.
    Matched MeSH terms: Neutrons
  15. Fulltext In-situ compositional analysis and provenance study of the historic terengganu stone (the inscribed stone “Batu Bersurat”) using neutron-induced prompt gamma-ray techniques (NIPGAT)
    Jaafar Abdullah, Roslan Yahya, Lahasen@Norman Shah Dahing, Hearie Hassan, Engku Mohd Fahmi Engku Chik, Mohamad Rabaie Shari, et al.
    Jurnal Sains Nuklear Malaysia, 2013;25(2):9-19.
    MyJurnal
    “Batu Bersurat Terengganu (inscribed stone)” is the oldest artifact with Jawi writing on it. The
    artifact proves that the Kingdom of Terengganu exist earlier than 1326 or 1386. To date, a lot of
    studies on the content of the inscription have been carried out by historians and archaeologists, but
    no scientific investigation about the material composition and its provenance has been performed.
    This paper focuses on the study of the origin of the Batu Bersurat Terengganu using NeutronInduced
    Prompt Gamma-Ray Techniques (NIPGAT). Portable NIPGAT system has been designed
    and developed based on volumetric measurement methods and it will be considered as a nondestructive
    testing. The system uses low activity of californium-252 (Cf-252) neutron radioactive
    sources, gamma ray spectroscopy and special computer software to carry out the investigation. The
    study found that the Batu Bersurat Terengganu is made of dolerite based on the elemental
    composition of the stone. Although most of the scientific data for the study of the origin are already
    obtained, but further research is still ongoing to complete the scope of this study.
    Matched MeSH terms: Neutrons
  16. Fulltext Neutron backscattered technique for quantification of oil palm fruit oil content
    Ismail Mustapha, Samihah Mustaffh, Md Fakarudin Ab Rahman, Roslan Yahya, Lahasen @ Norman Shah Dahin, Nor Pa’iza Mohd Hasan, et al.
    Jurnal Sains Nuklear Malaysia, 2015;25(1):24-28.
    MyJurnal
    Non-destructive and real time method becomes a well-liked method to researchers in the oil palm
    industry since 2000. This method has the ability to detect oil content in order to increase the
    production of oil palm for better profit. Hence, this research investigates the potential of neutron
    source to estimate oil content in palm oil fruit since oil palm contains hydrogen with chemical
    formula C55H96O6. For this paper, oil palm loose fruit was being used and divided into three
    groups. These three groups are ripe, under-ripe and bruised fruit. A total of 21 loose fruit for each
    group were collected from a private plantation in Malaysia. Each sample was scanned using
    neutron backscattered technique. The higher neutron count, the more hydrogen content, and the
    more oil content in palm oil fruit. The best correlation result came from the ripe fruits with r2=0.98.
    This research proves that neutron backscattered technique can be used as a non-destructive and
    real time grading system for palm oil.
    Matched MeSH terms: Neutrons
  17. The use of a neutron backscatter technique for in-situ water measurement in paper-recycling industry
    Hasan NM, Zain RM, Abdul Rahman MF, Mustapha I
    Appl Radiat Isot, 2009 Jul-Aug;67(7-8):1239-43.
    PMID: 19303310 DOI: 10.1016/j.apradiso.2009.02.020
    A bulk of used paper supplied to recycling industry may contain water in their internal voids. This is because the price of the used paper is currently based on their weight and it has a huge potential of suppliers to add with water in order to increase the price. Currently used methods for detecting moisture content in a paper are restricted to a sheet of paper only. This paper presents a non-intrusive method for quick and in-situ measurement of water content in a bulk of used paper. The proposed method extends the capability of common paper moisture gauge, by using a neutron device. A fast neutron source (Am-Be 241) and a portable backscattering neutron detector are used for water measurement. It theoretically indicates that the slow neutron counts can be correlated to the hydrogen or water level in a paper. The method has the potential of being used by the paper-recycling industry for rapid and non-destructive measurement of water in a bulk of used paper.
    Matched MeSH terms: Fast Neutrons; Neutrons
  18. Fulltext Synthesis of Highly Crystalline Multilayered Boron Niride Microflakes
    Ahmad P, Khandaker MU, Amin YM, Muhammad N
    Sci Rep, 2016;6:21403.
    PMID: 26892366 DOI: 10.1038/srep21403
    Boron niride microflakes of 2-5 μm in diameter and greater than 40 μm in length with multilayer structure and highly crystalline nature are synthesized in two states of catalysts and dual role of nitrogen at 1100 °C. Most of the microflakes are flat, smooth and vertically aligned with a wall-like view from the top. Transmission electron microscopy shows overlapped layers of microflakes with an interlayer spacing of 0.34 nm. The h-BN components of the synthesized microflakes are verified from B 1s and N1 s peaks at 190. 7 and 397.9 eV. Raman shift at 1370 (cm(-1)) and sharp peaks in the XRD pattern further confirm the h-BN phase and crystalline nature of the synthesized microflakes. Microflakes of h-BN with the above characteristics are highly desirable for the development of a solid state neutron detector with higher detection efficiency.
    Matched MeSH terms: Neutrons
  19. Fulltext Using 157Gd doped carbon and 157GdF4 nanoparticles in proton-targeted therapy for effectiveness enhancement and thermal neutron reduction: a simulation study
    Tabbakh F, Hosmane NS, Tajudin SM, Ghorashi AH, Morshedian N
    Sci Rep, 2022 Oct 18;12(1):17404.
    PMID: 36258012 DOI: 10.1038/s41598-022-22429-0
    There are two major problems in proton therapy. (1) In comparison with the gamma-ray therapy, proton therapy has only ~ 10% greater biological effectiveness, and (2) the risk of the secondary neutrons in proton therapy is another unsolved problem. In this report, the increase of biological effectiveness in proton therapy has been evaluated with better performance than 11B in the presence of two proposed nanomaterials of 157GdF4 and 157Gd doped carbon with the thermal neutron reduction due to the presence of 157Gd isotope. The present study is based on the microanalysis calculations using GEANT4 Monte Carlo tool and GEANT4-DNA package for the strand breaks measurement. It was found that the proposed method will increase the effectiveness corresponding to the alpha particles by more than 100% and also, potentially will decrease the thermal neutrons fluence, significantly. Also, in this work, a discussion is presented on a significant contribution of the secondary alpha particles in total effectiveness in proton therapy.
    Matched MeSH terms: Neutrons
  20. Fulltext Determination of neutronic parameters of RTP core using mcnp code
    Mohamad Hairie Rabir, Usang, Mark Dennis, Naim Syauqi Hamzah, Julia Abdul Karim, Mohd Amin Sharifuldin Salleh
    Jurnal Sains Nuklear Malaysia, 2013;25(1):45-59.
    MyJurnal
    The 1 MW TRIGA MARK II research reactor at Malaysian Nuclear Agency achieved initial
    criticality on June 28, 1982. The reactor is designed to effectively implement the various fields of
    basic nuclear research, manpower training, and production of radioisotopes. This
    paperdescribes the reactor parameters calculation for the PUSPATI TRIGA REACTOR (RTP);
    focusing on the application of the developed reactor 3D model for criticality calculation,
    analysis of power and neutron flux distribution and depletion study of TRIGA fuel. The 3D
    continuous energy Monte Carlo code MCNP was used to develop a versatile and accurate full
    model of the TRIGA reactor. The consistency and accuracy of the developed RTP MCNP model
    was established by comparing calculations to the experimental results and TRIGLAV
    code.MCNP and TRIGLAV criticality prediction of the critical core loading are in a very good
    agreement with the experimental results.Power peaking factor calculated with TRIGLAV are
    systematically higher than the MCNP but the trends are the same.Depletion calculation by both
    codes show differences especially at high burnup.The results are conservative and can be
    applied to show the reliability of MCNP code and the model both for design and verification of
    the reactor core, and future calculation of its neutronic parameters.
    Matched MeSH terms: Neutrons
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