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The present study was designed to gather evidence about the relationship between short-term debt, long-term debt with variables such as EPS, return on equity, return on assets and the ratio Q/B. This research was conducted in companies listed in Tehran Stock Exchange. Multiple linear regressions were used to test the hypothesis. In this study, 3 dependent variables, 4 control variables and 3 independent variables are used. Also, 12 hypotheses were provided for this study. The sample of the study consisted of 50 participate in a 5-year period of 2008 to 2012. The findings suggest that there is negative relationship between short-term debt, longterm debt and total debt with returns on equity. Also about four to six hypothesis it became clear that short-term debt and total debt to equity returns are negatively related. In testing hypotheses 7 and 9 showed that short-term debt, long-term debt and total debt is negatively associated with ROA. Also worth noting that in 10 to 12 hypothesis it is showed that there is negative relationship between short-term debt and total debt by Tobin's q.

This paper investigated the effects of imposed exchange rate arrangements on trade volume of BRICS countries. This study examined emerging economies, were consists of Brazil, Russia, India, China, and South Africa during the years 2001-2013 using the generalized gravity model and a two-step generalized method of moments, (GMM). The results indicated that applying different exchange rate arrangements has had significant influence on imports. Pegged (PG) and crawling pegged (CP) exchange rate arrangements had significant and positive effect on trade flow (export). Bilateral imports, improved with imposing managed floating (MF) arrangements. Free-floating (FL) arrangements have been meaningless, and a negative impact on the volume of bilateral trade (exports) between members. In BRICS countries, imposing pegged exchange rate arrangements improved bilateral trade toward export and inversely free-floating arrangements improved bilateral trade toward import.

The

The radionuclide zirconium-89 can be employed for the positron emission tomography (PET). In this study 89Zr excitation function via 89Y(p,n)89Zr reaction was calculated by the TALYS-1.8 code based on microscopic level density model. The formation of 89Zr was simulated using the Monte Carlo simulation code MCNPX to calculate the integral yield in the 89Y target body for threshold up to 40MeV incident-proton energy. The target thickness was based on calculation of the stopping power using the SRIM-2013 code matched to any incident-proton energy. The production yield of the 89Zr simulated with the Monte Carlo method for the 89Y(p,n)89Zr, 89Y(d,2n)89Zr, natSr(α,xn)89Zr and natZr(p,pxn)89Zr reactions and the results were in good agreement with published experimental results for the optimum energy range. An experimental yield of 53.1MB/µA for the 15MeV proton-induced on Y2O3 powder as a disk-target obtained for 1h irradiation at the AMIRS cyclotron.

The flow rate of coolant and the particle beam current are important when high beam current irradiations are intended for production of radionuclides. The beam current on

The

Ergosan contains 1% alginic acid extracted from two brown sea weeds. Little is known about the target organs and anatomical distribution of Ergosan (alginic acid) in fish. Therefore, feasibility of developing alginic acid nanoparticles to detect target organ in rainbow trout is interesting. To make nanoparticles, Ergosan extract (alginic acid) was irradiated at 30 kGy in a cobalt-60 irradiator and characterized by transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Results from TEM images showed that particle sizes of irradiated alginic acid ranged from 30 to 70 nm. The FTIR results indicated that gamma irradiation had no significant influence on the basic structure of alginic acid. Later, alginic acid nanoparticles were successively labelled with 67Ga-gallium chloride. The biodistribution of irradiated Ergosan in normal rainbow trout showed highest uptake in intestine and kidney and then in liver and kidney at 4- and 24-h post injection, respectively. Single-photon emission computed tomography (SPECT) images also demonstrated target specific binding of the tracer at 4- and 24-h post injection. In conclusion, the feed supplemented with alginic acid nanoparticles enhanced SPECT images of gastrointestinal morphology and immunity system in normal rainbow trout.

Medical linear accelerators, besides the clinically high energy electron and photon beams, produce other secondary particles such as neutrons which escalate the delivered dose. In this study the neutron dose at 10 and 18MV Elekta linac was obtained by using TLD600 and TLD700 as well as Monte Carlo simulation. For neutron dose assessment in 2020 cm2 field, TLDs were calibrated at first. Gamma calibration was performed with 10 and 18 MV linac and neutron calibration was done with 241Am-Be neutron source. For simulation, MCNPX code was used then calculated neutron dose equivalent was compared with measurement data. Neutron dose equivalent at 18 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 3.3, 4, 5 and 6 cm. Neutron dose at depths of less than 3.3cm was zero and maximized at the depth of 4 cm (44.39 mSvGy-1), whereas calculation resulted in the maximum of 2.32 mSvGy-1 at the same depth. Neutron dose at 10 MV was measured by using TLDs on the phantom surface and depths of 1, 2, 2.5, 3.3, 4 and 5 cm. No photoneutron dose was observed at depths of less than 3.3cm and the maximum was at 4cm equal to 5.44mSvGy-1, however, the calculated data showed the maximum of 0.077mSvGy-1 at the same depth. The comparison between measured photo neutron dose and calculated data along the beam axis in different depths, shows that the measurement data were much more than the calculated data, so it seems that TLD600 and TLD700 pairs are not suitable dosimeters for neutron dosimetry in linac central axis due to high photon flux, whereas MCNPX Monte Carlo techniques still remain a valuable tool for photonuclear dose studies.

Background & Aim: Diabetes because of its numerous complications has an extensive effect on patients’ quality of life. This study was conducted with the aim of determining the relationship between metabolic control indexes and quality of life of patients with type II diabetes in Shahroud-Iran. Material & Methods: It was a descriptive-correlational study. A total of 156 patients with type II diabetes were recruited by convenience sampling in 2013. Data was collected by diabetes-specific quality of life questionnaire. Indexes of metabolic control (hemoglobin A1C, fasting and non-fasting blood glucose, triglycerides, cholesterol, LDL and HDL) were also controlled. Data was analyzed by Pearson correlation coefficient and chi-square tests using SPSS-PC (v.16). Results: In this study the mean score of quality of life was 164.53±63.21 and the mean score of HgA1C was 8.65±1.55. A significant relationship was found between quality of life and all indicators except LDL (p

To develop a new biosensor for measurement of superoxide free radical generated in radiolysis reaction, three combinations of SOD-based biosensors including Au/Cys/SOD, Au/GNP/Cys/SOD and Au/GNP/Cys/SOD/Chit were fabricated. In these biosensors Au, GNP, Cys, SOD and Chit represent gold electrode, gold nano-particles, cysteine, superoxide dismutase and chitosan, respectively. For biosensors fabrication, SOD, GNP, Cys and Chit were immobilized at the surface of gold electrode. Cyclic voltametry and chronoamperometry were utilized for evaluation of biosensors performances. The results showed that Au/GNP/Cys/SOD/Chit has significantly better responses compared to Au/Cys/SOD and Au/GNP/Cys/SOD. As a result, this biosensor was selected for dosimetry of ionizing radiation. For this purpose, thallium 201 at different volumes was added to buffer phosphate solution in electrochemical cell. To obtain analytical parameters of Au/GNP/Cys/SOD/Chit, calibration curve was sketched. The results showed that this biosensor has a linear response in the range from 0.5 to 4 Gy, detection limit 0.03 μM. It also has a proper sensitivity (0.6038 nA/Gy), suitable long term stability and cost effective as well as high function for radiation dosimetry.

Cerium-141 [T 1/2 = 32.5 days, β 1 = 580.4 keV (30 %), β 2 = 435.0 keV (70 %), γ = 145.4 keV (48 %)], has been introduced as a radionuclide for therapy while can be used in diagnosis as well. In this study, nuclear model calculation on 141Ce production was investigated via the 140Ce(d,p)141Ce, 142Ce(d,dn)141Ce, 141Pr(n,p)141Ce, and 140Ce(n,γ)141Ce nuclear reactions. 140Ce was irradiated by thermal neutron at the Tehran Research Reactor according to the 140Ce(n,γ)141Ce reaction. In addition, the obtained activity of the produced 141Ce was compared with the theoretical calculations. The results showed that the end of bombardment activities of 141Ce is 631.64 MBq theoretically and 611.60 MBq experimentally for ceria powder. The activities of similar samples of ceria (CeO2) powder in two forms of nano-particles (nanoceria) and bulk were compared after bombardment by thermal neutrons. The results showed that activities of nanoceria were less than the bulk form of ceria.

A novel approach is introduced to generate simulated ground motion records by considering spectral acceleration correlations at multiple periods. Most of the current reliable Ground Motion Record (GMR) simulation procedures use a seismological model including source, path and site characteristics. However, the response spectrum of simulated GMR is somewhat different when compared with the response spectrum based on recorded GMRs. More specifically, the correlation between the spectral values at multiple periods is a characteristic of a record which is usually different between simulated and recorded GMRs. As this correlation has a significant influence on the structural response, it is needed to investigate the consistency of the simulated ground motions with actual records. This issue has been investigated in this study by incorporating an optimization algorithm within the Boore simulation technique. Eight seismological key parameters were optimized in order to achieve approximately the same correlation coefficients and spectral acceleration between two sets of real and simulated records. The results show that the acceleration response spectra of the synthetic ground motions also have good agreement with the real recorded response spectra by implementation of the proposed optimized values.

Enterotoxigenic Escherichia coli (ETEC) strains are the most common cause of bacterial diarrhea in children in developing countries and travelers to these areas. Enterotoxins and colonization factors (CFs) are two key virulence factors in ETEC pathogenesis, and the heterogeneity of the CFs is the bottleneck in reaching an effective vaccine. In this study, a candidate subunit vaccine, which is composed of CfaB, CssA and CssB, structural subunits of colonization factor antigen I and CS6 CFs, labile toxin subunit B, and the binding subunit of heat-labile and heat-stable toxoid, was designed to provide broad-spectrum protection against ETEC. The different features of chimeric gene, its mRNA stability, and chimeric protein properties were analyzed by using bioinformatic tools. The optimized chimeric gene was chemically synthesized and expressed successfully in a prokaryotic host. The purified protein was used for assessment of bioinformatic data by experimental methods.

Gold-199 is a promising theranostic radionuclide for targeted radioimmunotherapy as well as for scintigraphy and dosimetry. 199Au can be produced in two methods in the direct and indirect routes of the reactor production via 197Au(n,γ)198Au(n,γ)199Au as the direct or 198Pt(n,γ)199Pt→199Au as the indirect method. This investigation described the development of a method for the reactor production of no-carrier-added (NCA) 199Au through neutron activation of natural Pt in Tehran Research Reactor (TRR) at a thermal neutron flux of 3.5 × 1013 n cm−2 s−1. Also, in this paper, the activity of 199Au has been estimated using the MCNPX code. In this case, first, the reactor core is simulated. Then the calculated results are compared with the corresponding experimental values. Moreover, two different chemical separation methods are investigated experimentally in details.

Degradation of diclofenac (DCF) from aqueous solution was investigated by the heterogeneous electro-Fenton (EF) process using magnetic single-walled carbon nanotubes (MSWCNTs) as a new catalyst. The effect of parameters including initial pH, current density, initial catalyst concentration, the initial concentration of DCF and air flow rate on the efficiency of DCF removal and electrochemical production of H2O2 were studied. A removal efficiency of 97.8% for DCF and 71.12% for COD was obtained at an initial pH of 5, current density of 20 mA/cm2, MSWCNTs concentration of 80 mg/L, DCF concentration of 10 mg/L, air flow rate of 1 mL/min and reaction time of 120 min. Regarding the removal of DCF and COD, and production of H2O2, the heterogeneous EF process with MSWCNTs catalyst showed higher activity and efficiency than other electro-catalytic degradation systems. The stability tests of MSWCNTs after 5 time application confirmed its performance potential for long-term degradation of DCF in aqueous solutions. Intermediate products such as 2,3-dichlorobenzene and 2,4-dichlorophenol were identified by gas chromatography-mass spectrometry (GC–MS). Based on the identification of reactive species and the intermediate products, a possible mechanism of removal and degradation pathways for DCF was suggested.

A nanostructured Y(III) ion imprinted polymer (IIP) was synthesized by preparing a complex of Y(III) ions with 1,4-dihydroxy-9,10-anthraquinone (QZ) as a chelating agent. The Y(III) ion was found to form a 1 : 1 stable complex with QZ in 2-methoxyethanol solution. The prepared complex was then copolymerized with ethylene glycoldimethacrylate (cross-linking monomer), 2-hydroxyethyl methacrylate (functional monomer) and 2,2-azobis-isobutyronitrile (initiator) via a precipitation polymerization method. The imprinted Y(III) ion was removed using a 3 mol L−1 HCl solution to obtain leached IIP nanoparticles. Non-imprinted polymer particles were similarly prepared without Y(III) ions. The polymers were characterized by Fourier transform IR spectroscopy, scanning electron microscopy (SEM), dispersive X-ray spectroscopy, thermogravimetric analysis and N2 sorption–desorption isotherms. The SEM images of synthesized polymers exhibited nano-patterns. The effect of several parameters such as solution pH, sorption and desorption time, type, concentration, and volume of eluent on the extraction were investigated and optimized one variable at a time. The optimum pH for maximum sorption was 8.9. The maximum sorbent capacity of the IIP was 18.05 mg g−1. Following desorption, Y(III) was determined by inductively coupled plasma-atomic emission spectroscopy. A limit of detection and relative standard deviation (n = 6) of 0.9 ng mL−1 and 2.2%, respectively, were obtained. The method was applied in the determination of yttrium in a certified reference material and a radioyttrium sample to demonstrate the accuracy and applicability of the presented method.

In this study, a Monte Carlo code was used to simulate a proton beam flux to calculate the 94m Tc production yield from the 94 Mo(p,n) 94m Tc reaction. An experimental yield of 3.465 GBq/μAh was measured for 48 min of irradiation at 1 μA. An estimated value of 3.048 GBq/μAh was calculated for the yield produced based on the MCNPX proton flux in the same situation. These results demonstrate the usefulness and precision of MCNPX as a tool to design targets for the production of PET radionuclides. The yield of isotopic impurities from the 94 Mo(p,xn) 94g, 93m, 93g Tc reactions was also calculated by the MCNPX code.

Radioyttrium (containing 86Y, 87Y and 88Y) was produced by irradiating a natSrCO3 target with 15 MeV proton beam at a current of 30 µA for 12 min. A synthesized ion imprinted (IIP) and control polymer (CP) nanoparticles as sorbents were used for the separation of radioyttrium from strontium. The sorbents were characterized by Fourier Transform Infra-red spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray spectroscopy (EDX), Thermogravimetric analysis (TGA) and Surface area analysis. Effect of various parameters such as pH, mass sorbent, nature and volume of eluent were investigated on the percent extraction of radioyttrium ion using IIP and CP particles. Chemical and radionuclidic purity were determined by ICP-AES and HPGe detector gamma-ray spectrometry, respectively. The radioyttrium recovery yield was 99.5% and the stable Sr content in the final product was estimated to be 4.5 µg mL−1. In conclusion, the suggested method in this manuscript can be used for the production of other 86/87Y radionuclides.

In this study, the transmutation adiabatic resonance crossing (TARC) concept was estimated in 99Mo radioisotope production via radiative capture reaction in two designs. The TARC method was composed of moderating neutrons in lead or a composition of lead and water. Additionally, the target was surrounded by a moderator assembly and a graphite reflector district. Produced neutrons were investigated by (p,xn) interactions with 30 MeV and 300 μA proton beam on tungsten, beryllium, and tantalum targets. The 99Mo production yield was related to the moderator property, cross section, and sample positioning inside the distinct region of neutron storage as must be proper to achieve gains. Gathered thermal flux of neutrons can contribute to molybdenum isotope production. Moreover, the sample positioning to gain higher production yield was dependent on a greater flux in the length of thermal neutrons and region materials inside the moderator or reflector. When the sample radial distance from Be was 38 cm inside the graphite region using a lead moderator design, the production yield had the greatest value of activity, compared with the other regions, equal to 608.72 MBq/g. Comparison of the two designs using a Be target revealed that the maximum yield occurred inside the graphite region for the first design at 38 cm and inside the lead region for the second design at 10 cm. The results and modeling of the new neutron activator were very encouraging and seem to confirm that the TARC concept can be used for 99Mo production in nuclear medicine.

Purpose To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists' contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer.

The widely used Monte Carlo simulation code Monte Carlo N-Particle System (MCNPX) has been utilized to simulate the production of 67Gallium via multiple nuclear reaction channels. Based on the MCNPX-generated, energy-dependent proton flux within a Zn target during irradiation, the 67Ga production yield was determined. Theoretical calculations of the production yield using the stopping power from the SRIM (stopping and range of ions in matter) code were compared to the measurements from the MCNPX code. These results were in good agreement with reported data, thus confirming the usefulness and accuracy of MCNPX as a tool for the design and optimization of targets for the production of other radionuclides.

Monte Carlo simulations and TLD dosimetry have been performed to determine the dose distributions along the central axis of the 12 mm COMS eye plaques loaded with IRA1-103Pd seeds. Several simulations and measurements have been employed to investigate the effect of Silastic insert and air in front of the eye on dosimetry results along the central axis of the plaque and at some critical ocular structures. Measurements were performed using TLD-GR200A circular chip dosimeters in a PMMA eye phantom. The central axis TLD chips locations were arranged in one central column of eye phantom, in 3 mm intervals. The off-axis TLD chips locations were arranged in three off-axis columns around the central axis column. Version 5 of the MCNP code was also used to evaluate the dose distribution around the plaque. The presence of the Silastic insert results in dose reduction of 14% at 5 mm; also about 7% dose reduction appears at the interface point, due to the air presence and lack of the scattering condition. The overall dosimetric parameters for the COMS eye plaque loaded with new palladium seeds are similar to a commercial widely used seed such as Theragenics200. As the dose calculations under TG-43 assumptions do not consider the effect of the plaque backing and Silastic insert for accurate dosimetry, it's suggested to apply the effect of the eye plaque materials and air on dosimetry results along the central axis of the plaque and at some critical ocular structures.

The purpose of this study is to perform absorbed dose calculations based on Monte Carlo simulations for a novel beta emitter bioglass Ho-166 seed which is proposed for treating small hepatocellular carcinomas (HCCs). The bioactive glass seed has been developed by use of the sol–gel method. Monte Carlo simulations were carried out for the seed using the version 5 of the (MCNP) Monte Carlo radiation transport code to investigate the dosimetric parameters recommended by the AAPM Task Group 60 (TG-60). Dose distributions due to the beta and photon radiation were obtained at different radial distances surrounding the source. The dose rate in water at the reference point was calculated to be 6.71±0.4 cGy h−1 μCi−1. The anisotropy function values ranging from 0.745 to 1.928 were obtained for radial distances of 0.3–8 mm and polar angles of 0°–90°. The 166Ho seed source can deliver high radiation doses to the tumor, while the short range of the beta particles limits damage to the adjacent normal tissue.

Several important synthetic parameters such as precursor concentration, reaction time are found to determine the growth of ZnO nanostructures. These reaction parameters can be tuned to produce a variety size of nanostructures. In this work we show the importance of these parameters on the size of synthesized zinc oxide nano-powders. ZnO nanoparticles are synthesized by the solid-state reaction using ZnSO4·7H2O and NaOH as the reagents. In this method Zn(OH)2 is the intermediate product of the reaction, we show that by adjusting the molar ratio of the reagents and grinding time, we can be removed this unwanted component in the final product so for obtaining pure ZnO nanostructures the calcinations process is not necessary, also we can tune the size of ZnO nanoparticles. XRD spectra of the nanoparticles demonstrate typical diffraction peaks of a well-crystalline Wurtzite ZnO structure transmission electron microscopic observations show that these nanoparticles are of hexagonal phase ZnO mostly in round shapes and he composition analysis by EDX indicate that final product is pure ZnO. In the optimum conditions by XRD analysis we see that the mean grain size of synthesized zinc oxide nano-particles is about 44 nm.

Previously, a promising $$ {\beta^- } $$ -emitting praseodymium-142 glass seed was proposed for brachytherapy of prostate cancer. In accordance with the previous study, a 142Pr capillary tube-based radioactive implant (CTRI) was suggested as a source with a new structure to enhance application of $$ {\beta^- } $$ -emitting radioisotopes such as 142Pr in brachytherapy. Praseodymium oxide powder was encapsulated in a glass capillary tube. Then, a thin and flexible fluorinated ethylene propylene Teflon® layer sealed the capillary tube. The source was activated in the Tehran Research Reactor by the 141Pr(n,γ) 142Pr reaction. Measurements of the dosimetric parameters were performed using GafChromic® radiochromic film. In addition, the dose rate distribution of 142Pr CTRI was calculated by modeling 142Pr source in a water phantom using Monte Carlo N-Particle Transport (MCNP5) Code. The active source was unreactive and did not leak in water. In comparison with the earlier proposed 142Pr seed, the suggested source showed similar desirable dosimetric characteristics. Moreover, the 142Pr CTRI production procedure may be technically and economically more feasible. The mass of praseodymium in CTRI structure could be greater than that of the 142Pr glass seed; therefore, the required irradiation time and the neutron flux could be reduced. A 142Pr CTRI was proposed for brachytherapy of prostate cancer. The dosimetric calculations by the experimental measurements and Monte Carlo simulation were performed to fulfill the requirements according to the American Association of Physicists in Medicine recommendations before the clinical use of new brachytherapy sources. The characteristics of the suggested source were compared with those of the previously proposed 142Pr glass seed.

Purpose: To investigate the dosimetric characteristics of accelerated partial breast irradiation technique by MammoSite® applicator using thermoluminescent dosimeter (TLD) and Monte Carlo simulation to comparing them with treatment planning system calculation for planning target volume (PTV) and organs at risk such as skin, lung and chest wall. Materials and Methods: The Monte Carlo MCNP-5 code was used to simulate dose rate in the PTV that is a MammoSite® balloon with 1 cm margin around it. Experimental dosimetry was carried out within a female-equivalent chest phantom with TLD dosimeter after insertion of 192 Ir source into the MammoSite® applicator. Three dimensional planning (TP) was done for dose delivery to the specific points within the phantom by means of FlexiPlan software. Results: Statistical comparisons were done between TP calculation, Monte Carlo simulation and TLD. Our results showed good agreement for surface doses between simulation and measurement. The mean skin dose for the simulation and TLD result was 61.7% and 56.8% of prescription dose, respectively. The maximum dose to the chest wall for Monte Carlo and TLD were 114.4% and 111.8% of prescription dose, respectively. The maximum dose to the lung for Monte Carlo and TLD results were 28.4% and 27.3% of prescription dose, respectively. Using Monte Carlo simulation and an average female chest phantom, it was possible to demonstrate the accuracy on the calculated dose rate in the PTV of a MammoSite® dose delivery system with 192 Ir HDR sources. Conclusions: The results showed acceptable agreement between simulation, treatment planning, and experimental dosimetry results.

In this study labeling EDTMP (ethylenediamine tetra(methylene phosphonic acid)) and HEDP (Hydroxyethylidene-1, 1-Diphosphonic Acid) as the carrier ligands with Scandium-47 were investigated. The biokinetics of the bone seeking of labeled ligands with Scandium-47 were assessed by measuring the skeletal absorbed dose and then the mice data extrapolated to human absorbed dose and compared with the 186/188Rhenium-HEDP, 153Samarium-EDTMP dosimetry data estimated by other researchers. Because the availability of 47Sc was limited we performed some preliminary studies using 46Sc.

The radioisotope

The high rate of hepatitis C virus (HCV) infection among transfusion related risk groups such as patients with inherited bleeding disorders highlighting the investigation on prevalent subtypes and their epidemic history among this group. In this study, 166 new HCV NS5B sequences isolated from patients with inherited bleeding disorders together with 29 sequences related to hemophiliacs obtained from a previous study on diversity of HCV in Iran were analyzed. The most prevalent subtype was 1a (65%), followed by 3a (18.7%),1b (14.5%),4(1.2%) and 2k (0.6%). Subtypes 1a and 3a showed exponential expansion during the 20th century. Whereas expansion of 3a started around 20 years earlier than 1a among the study patients, the epidemic growth of 1a revealed a delay of about 10 years compared with that found for this subtype in developed countries. Our results supported the view that the spread of 3a reached the plateau 10 years prior to the screening of blood donors for HCV. Rather, 1a reached the plateau when screening program was implemented. The differences observed in the epidemic behavior of HCV-1a and 3a may be associated with different transmission routes of two subtypes. Indeed, expansion of 1a was more commonly linked to blood transfusion, while 3a was more strongly associated to drug use and specially IDU after 1960. Our findings also showed HCV transmission through blood products has effectively been controlled from late 1990s. In conclusion, the implementation of strategies such as standard surveillance programs and subsiding antiviral treatments seems to be essential to both prevent new HCV infections and to decline the current and future HCV disease among Iranian patients with inherited bleeding disorders.

Background X-ray mammography is one of the general methods for early detection of breast cancer. Since glandular tissue in the breast is sensitive to radiation and it increases the risk of cancer, the given dose to the patient is very important in mammography. Objectives The aim of this study was to determine the average absorbed dose of X-ray radiation in the glandular tissue of the breast during mammography examinations as well as investigating factors that influence the mean glandular dose (MGD). One of the precise methods for determination of MGD absorbed by the breast is Monte Carlo simulation method which is widely used to assess the dose. Materials and methods We studied some different X-ray sources and exposure factors that affect the MGD. "Midi-future" digital mammography system with amorphous-selenium detector was simulated using the Monte Carlo N-particle extended (MCNPX) code. Different anode/filter combinations such as tungsten/silver (W/Ag), tungsten/rhodium (W/Rh), and rhodium/aluminium (Rh/Al) were simulated in this study. The voltage of X-ray tube ranged from 24 kV to 32 kV with 2 kV intervals and the breast phantom thickness ranged from 3 to 8 cm, and glandular fraction g varied from 10% to 100%. Results MGD was measured for different anode/filter combinations and the effects of changing tube voltage, phantom thickness, combination and glandular breast tissue on MGD were studied. As glandular g and X-ray tube voltage increased, the breast dose increased too, and the increase of breast phantom thickness led to the decrease of MGD. The obtained results for MGD were consistent with the result of Boone et al. that was previously reported. Conclusion By comparing the results, we saw that W/Rh anode/filter combination is the best choice in breast mammography imaging because of the lowest delivered dose in comparison with W/Ag and Rh/Al. Moreover, breast thickness and g value have significant effects on MGD.

Gold has two medically useful radioactive isotopes, 198Au and 199Au, for locally irradiating and killing tumor cells. 198Au radionuclide has been produced through the irradiation of the pure gold via 197Au(n,γ)198Au reaction in the Tehran Research Reactor at a thermal neutron flux of 4.5×1013ncm-2s-1 for the different irradiation times. In this paper, the activity of 198Au radionuclide has been determined using MCNPX-2.6 and TALYS-1.6 codes and also the theoretical approach. The calculated results were compared with the corresponding experimental values. The calculated results were in good agreement with the experimental data, thus the used codes can be used as a powerful tool to predict and optimize production conditions in reactor.

Gold-198 (βmax=0.96MeV (98.6%), γmax=0.412MeV (95.5%) and T1/2=2.7 days) is a well-known therapeutic beta emitter in the field of nuclear medicine, and is being used for the treatment of many different cancers. In the present study, the Bremsstrahlung exposure induced by 198Au in different human tissues, DNA and RNA has been calculated. The specific Bremsstrahlung constant (ΓBr), Probability of energy loss by beta during Bremsstrahlung emission (PBr) and Bremsstrahlung activity (Arelease)Br were estimated. We strongly recommend these parameters should be considered in absorbed dose calculations of radionuclide therapy via 198Au.

This study aims to determine AAPM TG-60 dosimetric quantities in regions surrounding the 103Pd stent wall by MCNP5 Monte Carlo code. The Palmaz-Schatz stent was modeled by a hollow cylinder of 17.89mm length (2mm diameter) with net surface very similar to real stent. The Dose deposited per photon (Gy), relative dose, Anisotropy function, F(r,θ), and radial dose function, gL(r), were described at AAPM TG-60 protocol were generated from these values and listed in tabular format. For benchmarking, the relative dose values were verified with TG-43 and EGS4 code results at identical conditions, relative to the radial distances from surface of the stent. There were noticeable results. These physical dosimetric parameters can be used in future treatment planning systems for IVBT.

Thulium-167, having a half-life of 9.25 d, is an important therapeutic radionuclide. It was produced via the natEr(p,xn)167Tm nuclear reaction by irradiation of a sedimented target with 15 MeV protons at a beam current of 20 μA. Radiochemical separation of 167Tm from a solution of the irradiated erbium target in hydrochloric acid was performed using di-(2-ethylhexyl) phosphoric acid (HDEHP) in n-hexane and in chloroform separately. The effect of different molarities of HDEHP on extraction efficiency was investigated. The radiochemical yield of 167Tm amounted to about 80 ± 5% while using n-hexane/HDEHP (1 M). The experimentally obtained production yield was about 3.2 MBq/μA h. It was comparable with the theoretical value of 4.1 MBq/μA h obtained from nuclear model calculations using the TALYS and EMPIRE codes.

The main aim of nanomedicine is to revolutionize the health care system and find effective approaches to fighting fatal diseases. Therapeutic beams, which are employed in radiation therapy, do not discriminate between normal and cancerous cells and must rely on targeting the radiation beams to specific cells. Interestingly, the application of nanoscale particles in radiation therapy has aimed to improve outcomes in radiation therapy by increasing toxicity in tumors and reducing it in normal tissues. This review focuses on approaches to nanotechnology-based cancer radiation therapy methods such as radionuclide therapy, photodynamic therapy, and neutron capture therapy. Moreover, we have investigated nanotechnology-based thermotherapy methods, including hyperthermia and thermoablation, as non-ionizing modalities of treatment using thermal radiation. The results strongly demonstrate that nanotechnology-based cancer radiation therapy and thermotherapy methods hold substantial potential to improve the efficacy of anticancer radiation and thermotherapy modalities.

Introduction: Some musculoskeletal disorders, fatigue and human errors are rooted in the unsuitable design of the tools. Appropriate design is based on anthropometric data adapted to the target population. In our country, due to lack of anthropometric databases, data from western countries are used. The aim of this project is to compare physical dimensions of the Iranian people with non-Iranian and also ultimately prepare a database based on our body dimensions so that Iranian experts use this internal standard to design and manufacture our tools and equipment. Materials and Methods: This is a cross-sectional observational study in which 384 female and 384 male students from Isfahan University of Medical Sciences in were randomly selected. 30 anthropometric variables were measured by anthropometer, calipers and balance. These data were analyzed by SPSS software, version 11.5 and the index percentile was calculated. The percentiles obtained in America and Britain were compared with our standards and the percentage of difference between them was determined. Results: The statistical anthropometric percentile was found as a database for both genders. This study compared British and American standards, showing the most significant difference between anthropometric variables of Iranian and non-Iranian people. Conclusion: The results of this study reveal that Iranian body dimensions are different from those of non-Iranian persons. Therefore, we can’t use the standards of other countries to design tools and devices for Iranian people. The prepared database can be used as an anthropometric information bank based on national standards.

Erbium-165 with 10.3 h physical half-life decays completely by electron capture to the ground state of stable isotope 165Ho and it is an ideal radio lanthanide for Auger electron therapy. Excitation function of 165Er via natEr(p,x)165Tm → 165Er, 166Er(p,2n)165Tm → 165Er, 165Ho(p,n)165Er and 165Ho(d,2n)165Er reactions were calculated using ALICE/ASH (Hybrid and GDH models) and EMPIRE 3.1 codes and then were compared with the reported measurement by experimental data and TENDL-2011. Physical yield and target thickness were evaluated with attention to excitation function, stopping power and SRIM code. 165Er was produced using the sedimentation technique through the natEr (p,x)165Tm → 165Er reaction. The deposited target was irradiated with 15 MeV proton beams at 20 μA current for 1 h. The 165Tm production yield was 26 MBq/μA h at the end of bombardment.

A radiochemical purification procedure was developed for the separation of enriched cadmium (111Cd and 112Cd) from natural copper that used as backing; and was based upon the chromatographic adsorption. The separation of copper from cadmium was studied in this work. The ions were selectively separated from aqueous solution. Ion-exchange chromatography was employed as a column (1.5 cm i.d. and 15 cm length) with AG1-X8 resin (chloride form, 100–200 mesh) and a flow rate of 1–2 ml/min throughout the separation. 6 M HCl media was used for the adsorption of Cd and Cu on the resin. Then, Cu was eluted by 2 M HCl and Cd by 100 ml 0.5 M HNO3. The amount of Cu and Cd ions in the final solution (0.5 M HNO3) were measured by pulse polarographic method and the concentration of Cu was found to be

198Au (βmax = 0.96 MeV (98.6 %), γmax = 0.412 MeV (95.5 %) and T1/2 = 2.7 days) is a radionuclide with very appealing characteristics. 198Au has been widely used to treat the uterus, bladder, cervix, prostate, melanoma, breast, skin and other cancers. In the present study, cationic 198Au+3 and nonionic 198Au0 are prepared following thermal neutron irradiation of commercially available natural gold compounds in Tehran Research Reactor via the natAu(n,γ)198Au reaction. The prospects in the production of pure 198Au0 and 198Au+3 for radionuclide therapy are discussed and effect of reduction on the activity of radioactive gold is evaluated. Au0 particles were synthesized via NaBH4 reduction of aqueous solutions of hydrogen tetrachloroaurate trihydrate. Then two quartz tubes were charged with cationic 198Au3+ and nonionic 198Au0. After irradiation by thermal neutrons, the samples were analyzed for a period of 1 month by liquid scintillation counter and high purity germanium detector. As a result, natAu3+ reduction process had no significant effect on the activity of the 198Au sample. In conclusions, natural gold thermal neutron activation cross section is reasonably high for medical application.

The radionuclide vanadium-48 (T1/2 = 16 d, β+= 49.5 %) could be employed to positron emission tomography. In this Study, 48V excitation function for the nat/49/48Ti(p,x)48V and the 48Ti(d,2n)48V nuclear reactions were calculated by ALICE/ASH code. Then recommended thickness of the targets according to the SRIM-2010 code was calculated; consequently, the theoretical integral yields were computed for all reactions by the computer software. As a result, the 48Ti(p,n)48V reaction was determined as the best reaction. Ti target was prepared by sedimentation method to produce 48V throughout accelerator proton bombardment.

The radionuclide iron-55 (T1/2 = 2.73 a) decays by electron capture and consists of small percentage of weak gamma rays. 55Fe can be employed for industrial, medical and agriculture applications. First, calculation of the excitation functions of iron-55 via the 55Mn(p,n)55Fe, 55Mn(d,2n)55Fe and 54Fe(α,n2p)55Fe reactions were performed and investigated by ALICE/ASH (hybrid model) and EMPIRE (3.1 Rivoli) codes. Then the required thickness of the target was calculated by the SRIM code; moreover, the theoretical physical yields of 55Fe production reactions were obtained. Consequently, the best reaction, 55Mn(p,n)55Fe, was suggested to take full benefit of the excitation function and to avoid formation of radioactive and non-radioactive impurities as far as possible. Furthermore, the optimum energy range were predicted to be 2–18 MeV and the theoretical physical yield were obtained to be 0.35 MBq/μA h. Lastly, manganese dioxide (MnO2) powder was used to prepare the thick layer; it was deposited on an elliptical copper substrate by means of sedimentation method. Target was irradiated at 20 μA current and 18 MeV proton beam. The radioactivity of 55Fe was determined via X-ray detector.

We here presented a method for zirconium-89 production using a low-energy cyclotron. The half-life of 89Zr (T1/2 = 78.4 h) is suitable for immunoPET. 89Zr was produced via the 89Y(p, n)89Zr nuclear process at 20 μA current and 15 → 5 MeV protons beam (20 min). Yield of about 60.77 MBq 89Zr per μAh was experimentally obtained. Also, excitation functions and theoretical yields via 89Y(p, n)89Zr, 89Y(d, 2n)89Zr, natSr(α, xn)89Zr and 90Zr(n, 2n)89Zr reactions were calculated by EMPIRE (version 3.1 Rivoli), ALICE/ASH (pre-equilibrium and equilibrium) and TALYS-1.26 (direct, pre-equilibrium, and equilibrium) codes and TENDL-2010 database. The obtained results have been discussed and compared with the available experimental data.

Vanadium-48 was produced through the irradiation of the natural titanium target via the natTi(p, xn)48V reaction. The titanium target was irradiated at 1 mA current and by a 21 MeV proton beam for 4 hours. In this paper, the activity of 48V, 43Sc, and 46Sc radionuclides and the efficacy of the 47Ti(p, g), 48Ti(p, n), and 49Ti(p, 2n) channel reactions to form 48V radionuclide were determined using MCNPX code. Furthermore, the experimental activity of 48V was compared with the estimated value for the thick target yield produced in the irradiation time according to MCNPX code. Good agreement between production yield of the 48V and the simulation yield was observed. In conclusion, MCNPX code can be used for the estimation of the production yield.

61Cu is positron emitter and can be used as the PET and molecular imaging. In this study cyclotron production of 61Cu via 61Ni(p,n)61Cu, natNi(p,x)61Cu, natNi(d,x)61Cu, natNi(α,x)61Cu, natZn(p,x)61Cu and 59Co(α,2n)61Cu reactions was investigated. The ALICE/ASH (hybrid and GDH models) and TALYS-1.2 codes were used to calculate excitation functions for proton, alpha and deuteron induced on natNi, proton on 61Ni and natZn and also alpha-particle on 59Co targets that lead to the production of 61Cu radioisotopes using intermediate energy accelerators. In addition, we compared the data obtained from in this study with the reported measurement by experimental data. Moreover, optimal thickness of the targets and physical yield were obtained by stopping and range of ions in matter code for each reaction. Eventually 61Ni(p,n)61Cu and 59Co(α,2n)61Cu reaction to produce 61Cu in no-carrier added state with high production yield was suggested. Finally the natNi(p,x)61Cu reaction was employed to test the target preparation using electroplating technique.