Atom Indonesia (E-Journal)
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Correlations Between Body Weight and Size-Specific Dose Estimate on Thoracic Computed Tomography Examination
Full text linkThe dose received by a patient on CT examination is expressed in size-specific dose estimates (SSDE) which is a function of the patient diameter, x-ray attenuation, and scanner output (volume computed tomography dose index, CTDIvol). Patient diameter and x-ray attenuation are represented as water equivalent diameter (Dw). We conducted the research to analyze the relationships between body weight and Dw, CTDIvol, and size-specific dose estimates (SSDE) in contrast-enhanced thorax examinations. We used images from 100 patients (50 women and 50 men patients) whose weight range from 2.8 kg to 80 kg. The values of Dw, CTDIvol, and SSDE were automatically calculated from axial CT images using the IndoseCT software. Statistical analysis showed that the patient's body weight correlates linearly with the Dw. The linearity coefficient (R2) values for body weight and Dw is 0.43 (women) and 0.55 (men). However, weight was independent of the patient dose in terms of CTDIvol and SSDE. This was because the CT system used tube current modulation (TCM), which automatically adapted the tube current to patient size, resulting in a relatively constant dose regardless of the patient size (Dw)
Skin Dosimetric Comparison of 3DCRT and IMRT Planning for Post-Mastectomy Breast Radiotherapy
Full text linkBreast cancer is the most common cancer for incidence and mortality among females globally and in Indonesia. Mastectomy is still the most common surgery for female breast cancer in Indonesia. After the mastectomy, several patients will receive a whole breast radiotherapy session. About 68.75% of breast cancer patients in the radiotherapy department at Lavalette Hospital during 2019 had undergone the mastectomy. Radiotherapy treatment for breast cancer can be delivered using Intensity Modulated Radiotherapy (IMRT) or 3D-Conformal Radiotherapy (3DCRT) technique. This study is aimed to compare the skin dosimetric between IMRT and 3DCRT for post-mastectomy breast radiotherapy. Left-sided breast cancer patients who underwent radiotherapy at Lavalette Hospital during 2019 were included in this study, and 15 patients were selected. All patients received 50 Gy in 25 fractions over 5 weeks using 6 MV photons. The planning target volume (PTV) and organ at risk (OAR) were delineated. Skin with 3 mm thickness along PTV was also contoured for evaluating the dose delivered to the skin. The treatment planning was conducted using 3DCRT and 5 fields IMRT planning. The plans were optimized for at least 95% of the prescribed dose to cover 95% volume of the PTV. The mean dose and maximum dose were used for evaluating and comparing each plan. The skin’s mean dose from 3DCRT planning was 24.65 ± 4.12 Gy and 22.85 ± 3.68 Gy (p = 0.002) for IMRT planning. Meanwhile, skin maximum doses were 54.15 ± 0.68 Gy and 53.89 ± 1.05 Gy (p = 0.001) respectively for 3DCRT and IMRT planning. These results showed that IMRT offered a lower dose to the skin and a better skin-sparing effect than 3DCRT
Structure and Decay Properties of Th Isotopes Using E-RMFT Formalism
Full text linkIn the present scenario, the search for the thermally fissile nuclei is crucial and also important not only for the research background of nuclear physics but also for the great social and economic impact on the country. Many theoretical works have been performed to analyze a series of Th and U-isotopes and found that some of these isotopes are stable against α-decays and spontaneous fission. Here, we have chosen the isotopic chain of Th-nuclei for the present analysis using relativistic mean-field formalism. The work also explores a few stable isotopes in this region of the nuclear landscape, which is crucial for understanding the exotic region of the nuclear landscape. The objective of this work is to study the bulk properties such as binding energies, root mean square charge radii, neutron-proton radii, neutron skin-thickness as well as intrinsic properties such as excitation energy and specific heat for the 216-238Th-isotopic chain. Furthermore, the stability of these isotopes is investigated through their possible decay chain analysis. The relativistic mean-field theory was used to obtain the nuclear bulk properties, namely, binding energies, root-mean-square charge radii, neutron skin-thickness, and excitation energy. The steady solution of the temperature-dependent effective relativistic mean-field equations was obtained self-consistently by taking different inputs of the initial deformations. All the calculations were done for NL3, FSUGarnet and IOPB-I parameter sets for 216-238Th-isotopes. The decay energy of α (Qα) and β-decay (Qβ) were calculated from the binding energies and were further used to obtain the corresponding half-lives. We have analyzed the structural and decay properties of 216-238Th isotopes. The excitation energy and specific heat are also estimated for these considered nuclei by using the temperature-dependent effective relativistic mean-field (E-RMFT) formalism for NL3, FSUGarnet and IOPB-I parameters sets. The calculated results are compared with the available experimental data and found similar observations for all the parameter sets at a given temperature. The excitation energy study signifies the shell melting point where maybe the shape transition occurs. Three phenomenological formulae such as Viola-Seaborg, Royer and modified universal decay law are adopted for the calculation of α-decay half-lives. We found lower values of α-decay half-lives indicating a higher rate of β-decay for the isotopic chain
Potentials of Alginates as Capping Agent for Oral Colon Delivery of Radiosynthesized Silver Nanoparticles: A Review
Full text linkRadiosynthesized silver nanoparticles (AgNPs) offer benefits for treatment of chronic colon inflammation due to their anti-inflammatory activity. Targeted delivery of AgNPs to the colon allows topical treatment at high concentration but at reduced systemic side effects. Meanwhile, related to drug administration, oral route is a common method. However, the physiology of the gastrointestinal (GI) tract limits the AgNPs ability to achieve their therapeutic level. This is specifically related to the acidic environment of the stomach and mucus layer of the GI tract. Concurently, alginates are one of the most extensively explored biomaterial classes for drug delivery system due to its biocompatibility, gel-forming ability at mild condition, anionic nature, sensitivity, and mucoadhesiveness. In this review we provide an overview of appropriate features of alginates as capping agent for oral delivery of radiosynthesized AgNPs to the colon. As capping agents, alginates play multiple roles specific to its processing stages, i.e., radiosynthesis, stabilization of nanoparticle system, and oral colon delivery devices of AgNPs. Additionally, we describe outstanding features of alginates as capping agents for drug delivery device as well as the positive contributions of radiation processing on improving the functional effects of alginate
Systematic Projected Shell Model Study of Even-Even Dysprosium Isotopes
Full text linkBack-bending phenomenon is one of the important phenomena usually seen at high spin states of even - even heavy nuclei. As a result, any changes in the behavior of nuclear rotation, such as increase in moment of inertia versus rotational frequency can be shown in the usual back-bending plots which have been studied in many papers before. In this paper we show for the first time that these changes can be seen in the ratio of electromagnetic reduced transition probabilities B (E2) and B (M1) in even - even 152-164Dy isotopes using the Projected Shell Model (PSM) theory. The electric quadrupole transition probability B (E2) and the magnetic dipole transition probability B (M1) moments are sensitive to nuclear shape deformation and nuclear charge distribution, respectively. Our findings confirm the well-known back-bending previously seen and are in good agreement with experimental results. While intrinsic quadrupole moments are constant for each Dy isotope, the new findings show that spectroscopic quadrupole moments are increasing with spin
Response Surface Optimization of Gamma Irradiation Synthesis of Alginate-Stabilized Silver Nanoparticles Without Addition of a Hydroxyl Radical Scavenger
Full text linkThe use of isopropanol as a hydroxyl radical scavenger on the radiosynthesis of alginate-stabilized silver nanoparticles (AgNPs) can limit its application in nanomedicine. Meanwhile, optimum condition for gamma irradiation synthesis of alginate-stabilized AgNPs without addition of a hydroxyl radical scavenger has not been reported yet. In this study, the optimization of this process was carried out using response surface methodology (RSM) combined with Central Composite Design (CCD). The three processing conditions, i.e. radiation dose, precursor silver ion concentration, and alginate concentration were selected as decision variables to maximize two responses in terms of the conversion yield and AgNP concentration responses. The results indicated that the regression model of conversion yield and AgNP concentration fit linearly with the two-factor interaction and the linear model, respectively. The significant effect of the alginate factor on the conversion yield indicates the dual stabilizing–scavenging role of the alginate. The optimum conditions derived from CCD-RSM were obtained at a 20 kGy radiation dose, 7.78 mM precursor silver ion concentration, and 1.2 % (w/v) alginate concentration with the desirability of 0.731. The actual experimental results were 65.43% conversion yield and 480.91 ppm AgNP concentration, which were within the prediction interval at confidence of 95 %. The AgNPs under the optimum condition had a spherical shape, 97.4 % volume of size distribution at 6.50-28.21 nm, and zeta potential of -28.3 mV
Determination and Distribution Map for Radionuclides in Soil Samples from Different Location by Gamma Spectrometry Using Software Analysis
Full text linkThe fundamental goal of the current study is to determine the mean activity concentrations of natural and artificial radionuclides of 226Ra, 232Th, 40K, and 137Cs using gamma spectrometry for three locations, in Egypt, Saudi Arabia, and Iraq, which are significant and vital countries in the Middle East. The mean absorbed dose rate equals 22.35, 28.96, and 43.34 nGy h-1 for Egypt, Saudi Arabia, and Iraq. The results are consistent with international reports. The dose contribution percentages for investigated locations are 24 %, 30 %, and 46 % for Egypt, Saudi Arabia, and Iraq, respectively. The obtained results were clarified by statistical measurements using one-way ANOVA test to determine the distribution and differences between the averages of the three groups under study, as they may be influenced by geological variations and human intervention. It was found that the Iraq samples followed a symmetrical, standard normal distribution, while samples from Egypt and Saudi Arabia did not. Statistically significant differences were found between the data from the three countries
Detection of Radon Exhalation from Various Building Materials Using CR-39, RAD7, and Biosensors
Full text linkStudy aimed to design and manufacture two biosensors, namely BIOS-I and BIOS-II, for 222Rn and Pb+2 measurements in building materials and soil samples. For comparison, the conventional detectors of RAD7 and CR-39 were used. The biosensor material used was based on ssDNA rich guanine or primer. The two biosensors have a difference in the sequence of the nitrogenous bases. The measurement revealed that the average of 222Rn exhalation by the BIOS-Ι was 373.30 Bqm-3, while the BIOS-ΙΙ was 342.29 Bqm-3. The average 222Rn exhalation measured by the CR-39 detector was 326.17 Bqm-3, whereas by the RAD7 detector it was 319.95 Bqm-3. This study found that 222Rn exhalation in the Indian and Chinese granites, soil, and Iraqi mosaic samples was higher than the limits recommended by WHO, while the rest of the samples were within the permissible limits. It is also known that there is a very weak positive correlation between BIOS-Ι or BIOS-ΙΙ and humidity, while a very weak negative correlation was found between them and temperature. There is a very strong positive correlation between radon exhalation recorded by RAD7 and humidity. On the other hand, there are no statistically significant differences between BIOS-I and BIOS-II at (level 0.01), while there are statistically significant differences between BIOS-I and CR-39 or RAD7 at level 0.01. It was concluded that the manufactured biosensors have better detection for radon than RAD 7 and CR-39 detectors
