Atom Indonesia (E-Journal)
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Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D
Get PDFThe magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at vr = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°.to 44° Received: 03 March 2014; Revised: 22 May 2014; Accepted: 30 May 201
Solution of Dirac Equation for q-Deformed Eckart Potential with Yukawa-type Tensor Interaction for Spin and Pseudospin Symmetry Using Romanovski Polynomial
Get PDFThe motion of a nucleon in q-deformed Eckart potential field coupled with Yukawa-type tensor potential is described by using Dirac equation. The bound state solutions of Dirac equation for q-deformed Eckart potential with Yukawa-type tensor potential under exact spin- and pseudospin-symmetric limit are obtained using finite Romanovski polynomials. The approximate relativistic energy spectra are exactly obtained within the approximation scheme of centrifugal term. The relativistic energy is negative for pseudospin symmetry and positive for spin symmetry. The radial component of Dirac spinors are obtained in terms of Romanovski polynomials under exact spin- and pseudospin-symmetric conditions. The relativistic energy spectrum for the exact spin-symmetric case reduces to non-relativistic energy spectrum in the non-relativistic limit.Received: 23 October 2013; Revised: 02 November 2013 Accepted: 10 November 201
Natural Radioactivity in Some Food Crops from Bangka-Belitung Islands, Indonesia
Get PDFNatural radioactivities of food crops are the main sources of internal radiation exposure in humans. Bangka-Belitung islands of Indonesia has a higher natural background radioactivity than typical areas because of tin mining activities.The study was carried out to evaluate the natural radioactivity concentration in several food crops grown in Bangka and Belitung Islands. Food samples collected from Bangka and Belitung Islands were analyzed by means of a gamma spectroscopy for natural radionuclides 226Ra, 232Th and 40K. The annual intake of the food was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diets. The intakes of these radionuclides were calculated using the concentrations in Bangka-Belitung foods and annual consumption rates of these food. Annual intakes of these radionuclides were as follows: 226Ra = 190.00; 232Th = 633.79 and 40K = 2065.10 Bq/year. The annual internal dose resulting from ingestion of radionuclides in food was 0.205 mSv/year which is much lower than annual dose limit of 1 mSv for general public. The radionuclides with highest consumption is 40K followed by 232Th and 226Ra.Received: 21 October 2013; Revised: 22 April 2014; Accepted: 28 April 201
Radiation-induced DNA Double Strand Breaks and Their Modulations by Treatments with Moringa oleifera Lam. Leaf Extracts: A Cancer Cell Culture Model
Get PDFGamma radiation brings deleterious effects upon human cells by inducing oxidative stress and DNA damages. Antioxidants have been shown to confer protective effects on irradiated normal cells. Moringa oleifera Lam. is a widely used nutritional supplement with antioxidant activities. This report showed that antioxidant-containing supplements, in addition to protecting normal cells, could protect cancer cells against genotoxic effects of gamma radiation. γ-H2AX immunofluorescent foci were utilized as an indicator of radiation-induced DNA double strand breaks. MCF-7 human breast adenocarcinoma cells were irradiated with 2-8 Gy gamma radiation. A linear relationship between the formation of γ-H2AX foci and radiation dose was observed with an average of 10 foci per cell per Gy. A 30-minute pretreatment of the cells with either the aqueous or the ethanolic extract of M. oleifera leaves could partially protect the cells from radiation-induced DNA double strand breaks. A pretreatment with 500 µg/mL aqueous extract reduced the number of foci formed by 15% when assayed at 30 minutes post-irradiation. The ethanolic extract was more effective; 500 µg/mL of its concentration reduced the number of foci among irradiated cells by 30%. The results indicated that irradiated cancer cells responded similarly to nutritional supplements containing antioxidants as irradiated normal cells. These natural antioxidants could confer protective effects upon cancer cells against gamma radiation.Received: 08 November 2013; Revised: 01 March 2014; Accepted: 17 March 201
Biodistribution and Imaging of The 99mTc-Glutathione Radiopharmaceutical in White Rats Induced with Cancer
Get PDF99mTc-glutathione (99mTc-GSH) is a radiopharmaceuticalwhich is potentially used as a cancer diagnostic kit. As with other radiopharmaceuticals, before applied in humans, including in clinical trials, 99mTc-GSH needs to go through a series of preclinical trials in animal first. The preclinical trial which has been done in this study is the evaluation of the biological test on biodistribution and imaging of white rats (Rattus norvegicus) which had been induced with cancer. The aims of this research were to obtain data on biodistribution and to image the biodistribution of 99mTc-GSH at 1 hour, 3 hours, and 24 hours post-injection. Biodistribution resultsof 99mTc-GSHin the cancer at the timesof 1 hour, 3 hours, and 24 hours after injection were 0.66% ID/g, 0.95% ID/g, and 0.06% ID/g, respectively. This result shows that the highest accumulation of 99mTc-GSH in canceroccur at 3 hours post-injection. This value indicates that the optimal accumulation of the 99mTc-GSH occur in this time interval.In addition, the results of imaging test also show that the accumulation capacity of 99mTc-GSHin cancer is also highest at 3 hours post-injection.Received:16 January 2013; Revised:15 October 2013; Accepted: 16 October 201
Dose-Response Curve of Chromosome Aberrations in Human Lymphocytes Induced by Gamma-Rays
Get PDFChromosome aberration is a biomarker to predict the level of cell damage caused by exposure to ionizing radiation on human body. Dicentric chromosome is a specific chromosome aberration caused by ionizing radiation and is used as a gold standard biodosimetry of individuals over exposed to ionizing radiation.In radiation accident the dicentric assays has been applied as biological dosimetry to estimate radiation absorbed dose and also to confirm the radiation dose received to radiation workers.The purpose of this study was to generate a dose response curve of chromosome aberration (dicentric) in human lymphocyte inducedbygamma radiation. Peripheral blood samplesfrom three non smoking healthy volunteers aged between 25-48 years old with informed consent were irradiated with dose between 0.1-4.0Gy and a control using gamma teletherapy source. The culture procedure was conducted following the IAEA standard procedures with slight modifications. Analysis of dose-response curves used was LQ model Y = a + αD + βD2. The result showed that α and β values of the curve obtained were 0.018± 0.006 and 0.013 ± 0.002,respectively. Dose response calibration curve for dicentric chromosome aberrations in human lymphocytes induced by gamma-radiation fitted to linear quadratic model. In order to apply the dose response curve of chromosome aberration disentric for biodosimetry, this standar curve still need to be validatedReceived: 8 November 2013; Revised: 27 December 2013; Accepted: 31 December 201
Synthesis and Characterization of Poly(Amidoamine) Dendrimers Encapsulated 198Au Nanoparticles
Get PDFBrachytherapy or internal radiotherapy is one of many methods used for treatment of cancer. This modality requires an agent with radionuclides that emits α or β particle with a proper energy. 198Au (99% β max = 0.96 MeV and t1/2 = 2.69 days) is one of radionuclides that has been considered to be effective for the above-mentioned purpose. The purpose of this research was to synthesis and characterize poly(amidoamine) (PAMAM) G3.0 dendrimers encapsulated 198Au nanoparticles as a new brachytherapy agent. PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles was successfully synthesized by a bottom-up method using sodium borohydride as a reductor. Purification was then performed by a size exclusion chromatography in order to separate large Au nanoparticles that were formed outside the cavity of PAMAM G3.0 dendrimers. Prior to the synthesis of PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles, the synthetic procedure was first established by using a non-radioactive Au. The PAMAM G3.0 dendrimers encapsulated Au nanoparticles produced was then characterized by using an UV-Vis spectroscopy, a transmission electron microscopy (TEM), particle size analyzer (PSA), and an atomic absorption spectroscopy (AAS). Characterization results revealed that PAMAM G3.0 dendrimers encapsulated Au nanoparticles that were prepared from a reaction mixture of PAMAM G3.0 dendrimers and Au HAuCl4 with mol ratio of 2.8, was found to be a proper formula. It produced PAMAM G3.0 dendrimers encapsulated Au nanoparticles with diameter of 1.743 nm, spheris, uniform and drug loading value of 26.34%. This formula was then used in synthesis using radioactive Au, 198Au. Characterization results of PAMAM G3.0 dendrimers encapsulated 198Au nanoparticles gave a radiochemical purity of 99.4% and zero charge. Received: 04 December 2012; Revised: 18 December 2012; Accepted: 20 December 201
Arsenic Irradiation Induced Atomic Interdiffusion of InxGa1-xAs/InP Quantum Well Structures
Get PDFThe atomic intermixing of InxGa1-xAs/InP quantum well structures induced by arsenic irradiation has been investigated using photoluminescence (PL) measurement. The ion doses used were varried from 5x1011 As/cm2 to 1x1013 As/cm2. Also, the irradiation temperature were carried out from -200oC to 300oC. The samples were annealed under Argon flow in rapid thermal annealer (RTA) at 750oC for 60 second. The photoluminescence result showed that there was increase in energy shift at lower doses. However, the energy shift was saturated at higher dose. At elevated temperature implantation showed that the energy shift did not change significantly for all the samples (LM, TS, CS). In additon to this, the higher energy shift was observed in the Compressive Strain (CS) samples, but the lower of the energy shift was experienced in the Tensile Strain (TS) samples. Received: 06 September 2012; Revised: 27 November 2012; Accepted: 03 December 201
Effectiveness of Gamma Rays in Attenuating Rodent Malaria Parasites of Plasmodium berghei in Blood of Mice
Get PDFMalaria is a major public health problem in Indonesia. Therefore, an effective vaccine against this disease is actively being sought by using gamma rays to attenuate the parasites. However, the safety and efficacy of the resulting vaccine are dependent on the precise irradiation dose. The aim of this research was to determine the exact time when the parasites are attenuated by gamma ray exposure. Mice blood containing Plasmodium berghei of 5,0 X 107 parasites/ml was irradiated with gamma rays at doses of 0, 150, 175 and 200 Gy (doses rate of 380 Gy/h) and then was injected intraperitoneally to mice at 0, 1, 2, 3, and 4 h post irradiation. The parasitemia (parasite density) in mouse blood was observed starting with day 2 and repeated every 2-4 days up to 28 days. The survival of the mice was also observed during the experiment. The results showed that the pre-patent period advanced with exposing infected blood to 150 and 175 Gy irradiations, suggesting some degree of attenuation. The amount of radiation required to render the parasites non-viable is about 175 Gy for an inoculum of a number of parasites, but a delay of 4 h resulted in the death of parasites. There was no difference in the infectivity of irradiated parasite injected 1 h and 2 h post irradiation in terms of parasitemia and the survival of mouse. For a dose of 200 Gy which was injected 2 h post irradiation, no parasitemia was found in the blood and animals which died after times varying from 1 to 4 weeks. We concluded that irradiated parasites should be injected into the host within 1 h after irradiation.Received: 16 January 2013; Revised: 23 April 2013; Accepted: 24 April 201
In-vitro Degradation Behaviour of Irradiated Bacterial Cellulose Membrane
Get PDFBacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in–vitro degradation study in synthetic body fluid (SBF) of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure. Received: 05 December 2011; Revised: 24 September 2012; Accepted: 29 August 201