Maximum Effective Dose Research Articles

Molecular and phylogenetic analysis of a type K1 strain Trypanosoma evansi isolate from Nigerian cattle: An evaluation of the therapeutic effects of compounds from Brassica oleracea on the histopathology of infected wister rats

BackgroundUnderstanding the pathogenesis of animal trypanosomiasis can be improved by studying the genetics of bovine trypanosomes. Pathogenic animal trypanosomes are a major impediment to livestock production, with negative economic consequences spreading beyond Sub-Saharan Africa to subtropical regions of Northern Africa, Southeast Asia, and Central and South America. An atypical K1 strain of Trypanosoma evansi (T. evansi) isolates from infected cattle in Nigeria was analyzed. The therapeutic effect of phenolic-rich compounds on the histopathology of wistar rats infected with the K1 strain was studied. MethodsThe K1 strain T. evansi was analyzed molecularly using PCR and sequence analysis of the Spacer-1 ribosomal RNA gene. To assess the evolutionary relationship, this was phylogenetically compared to other species studied in different parts of the world. Thirty adult male wistar rats were divided into six groups of five each. Animals in group A served as the standard control (not infected). Group B animals were infected but not treated. Group C animals were infected and given 3.5 mg/kg body weight of the standard drug diminazene aceturate. Animals in groups D, E, and F were infected and treated with phenolic-rich compounds isolated from Brassica oleracea (B. oleracea) at concentrations of 100, 200, and 400 mg/kg body weight, respectively. The phytochemicals were extracted using standard analytical procedures, and GCMS analysis revealed the presence of phenolic-rich compounds. The animals were given 0.2 mg/ml trypanosome intraperitoneally, diluted with normal saline. The vital organs of the animals were harvested and histologically examined. ResultsThe nested PCR amplification of the trypanosome's ITS-1 region revealed a DNA amplicon of 627 base pairs. The rRNA nucleotide sequence was deposited in GenBank under the accession number MN462960. Basic Local Alignment search of the obtained ITS-1 rRNA sequences revealed that the K1 strain trypanosome and other strains from different regions have an evolutionary relationship. The phenolic-rich compounds had protective effects on the organs of infected animals, resulting in a decrease in parasitemia levels. They have anti-trypanosome activities at the minimum and maximum effective doses of 200 and 400 mg/kg body weight, respectively. ConclusionsThe K1 strain T. evansi was isolated from naturally infected cattle in this study. The results indicate that phenolic-rich compounds have anti trypanosoma activities capable of healing organ damage caused by trypanosomiasis.

Оценка мощности амбиентного эквивалента дозы на лесных участках в юго-западных районах Брянской области

The large areas of forests in the Bryansk region are still contaminated with radionuclides released due to the accident at the Chernobyl NPP in April, 1986. The recovery of the economic and ecosystems potentials in the contaminated areas is the need to create a favorable living conditions for the population. This involves a full range of remediation activities in the contaminated areas aimed at the forests protection and regeneration. The aim of the work is to assess the ambient dose equivalent rate (ADER) in forest sites located in the zone of radioactive contamination. More than 1 thousand forest sites in the south-western part of the Bryansk region were surveyed from 2019 to 2022. The ADER and the density of the soil contaminated by Cs-137 for every surveyed forest site are available. The relationship between the ADER and the density of the soil radioactive contamination in various sites was analyzed. The dose rates were normalized with respect to the density of soil contamination. The ADER rates in the Bryansk forest areas ranged from 0.07 to 3.15 mSv/h. No reliable difference between the ADER in the areas of coniferous and deciduous forests was observed. There was reliable linear relationship between ADER and the density of soil contaminated by Cs-137. During forestry operations in radioactive contaminated areas the maximum permissible external radiation effective dose was the dose accumulated for the whole period of work in the forest sites with the average density of soil contaminated by Cs-137 of 450 kBq/m2.

Implementing online position monitoring for prostate radiotherapy using an in-house position monitoring system: User experience and impact on workforce.

To evaluate the feasibility of prostate intrafraction motion monitoring using the SeedTracker real-time image guidance system in order to improve targeting accuracy in prostate radiotherapy. SeedTracker was used to monitor prostate gold fiducial seeds with kV x-ray imaging during radiotherapy in 30 patients. Feedback from radiation therapists was collected via the use of a user evaluation form. The impact on treatment time was established by using a record and verify system. The effective dose and a risk of exposure-induced cancer death (REID) were estimated for a 60-year-old patient when using the SeedTracker system. A total of 22 radiation therapists completed user evaluation forms. The time taken to prepare a reference data set for one patient varied with three (13.6%) radiation therapists taking less than 2 min, 10 (45.5%) between 2 and 4 min, eight (36.4%) between 4 and 6 min and one (4.5%) between 6 and 8 min. The useability of the SeedTracker system was reported as 'easy' by 21 (95.5%) radiation therapists and 'hard' by 1 (4.5%) radiation therapist. Mean treatment time changed from 6 to 7 min with prostate-only radiotherapy treatment and from 6.9 to 10.2 min with prostate and whole pelvis radiotherapy treatments. The maximum effective dose with the SeedTracker was 1.6276 mSv, and increase in REID was 0.007%. The SeedTracker real-time image guidance system is a feasible tool to use in radiotherapy departments to monitor and correct for prostate intrafraction motion.

Computational spectrometry and dosimetry, of neutrons and γ rays, outside a subcritical nuclear reactor with water and polyethylene moderators

An external neutron source is necessary to start up and run a subcritical thermal nuclear reactor. The external neutron source can be a neutron generator, a radionuclide having spontaneous fission or an isotopic neutrons source. Turning off the neutron generator or removing the neutron source shuts down the reactor. In subcritical reactors for teaching, fuel tubes and items for irradiation can be inserted or removed even when the reactor is running because are radiological safe. The aim of this work was to estimate, using Monte Carlo methods, the neutron and γ-ray spectra at five sites outside a Subcritical thermal neutron reactor Nuclear Chicago model 9000 using water and polyethylene moderators. In addition, the ambient dose equivalent and the ambient dose, for neutrons and γ-rays were calculated. For neutrons, the ambient dose equivalent were calculated with the neutron fluence-to-ambient dose equivalent coefficients from the ICRP 74 and the neutron fluence-to-ambient dose response of the neutron area monitor LB 6411; while, the ambient dose was calculated using the ICRU 95 neutron fluence-to-ambient dose coefficients. For γ-rays, was calculated the ambient dose equivalent using the ICRP 74 photon fluence-to-ambient dose equivalent coefficients; while, the ambient dose was calculated with the photon fluence-to-ambient dose coefficients from the ICRU 95. Outside the reactor, neutron spectra have fast, epithermal and thermal neutrons, and gamma ray spectra have γ rays induced in the inelastic scattering and capture of neutrons with the reactor materials. Neutron and γ-ray fluence rates and dose rates are larger in the water-moderated reactor. The ambient dose rates, due to neutrons and γ-rays, are smaller than the ambient dose equivalent, because the ambient dose resembles the maximum effective dose.

Assessing health risk associated with uranium in Rietspruit water, far West Rand goldfield, South Africa

Uranium, U, as a radiological and chemically toxic element has detrimental impacts on human health when ingested at elevated concentration in water. Effluents from an underground gold mine located in the head water region of the Rietspruit contaminated the stream with waterborne uranium. The Rietspruit is a tributary of the Vaal River and subsequently flows through residential and agricultural land. Water samples from the stream were collected and analysed using inductively coupled plasma mass spectrometry to determine the concentrations of dissolved U. The maximum concentration of U recorded was 781.9 µg/L at the mine from where it decreases with growing distance from the mine. Results from calculations showed that the maximum annual effective dose at the mine was above the regulatory limit for public exposure for all age groups. The radiological risk associated with consumption of untreated water from the Rietspruit is lower than the chemical risk. The chemical risk ranges from 0 to 37.2 while the highest life-time cancer risk was 1.7 E-03 for morbidity cancer risk and 1.1 E-03 for mortality cancer risk. The chemical risk analysis showed that within 24 km of downstream of the mine, stream users are exposed to toxic U levels. Therefore, adequate interventions by relevant government agencies are required.

ВЛИЯНИЕ ГИБРИДНЫХ ОЛОВООРГАНИЧЕСКИХ СОЕДИНЕНИЙ В МАКСИМАЛЬНО ЭФФЕКТИВНОЙ ДОЗЕ НА РОСТ И АКТИВНОСТЬ МЕТАСТАЗИРОВАНИЯ МЕЛАНОМЫ В16 У МЫШЕЙ ЛИНИИ C57BL/6

Metastasis is a complex multicomponent process that largely determines the effect of the tumor process on the body. The study of indicators of changes in the activity of metastasis under the influence of new antitumor agents is one of the most important tasks of experimental pharmacology and oncology. The effect of the organotin compounds (OOS) bis (3,5-di-tert-butyl-4-hydroxyphenylthiolate) dimethylolol (Me3) and (3,5-di-tert-butyl-4-hydroxyphenylthiolate) triphenylolol (Me5) was studied at the maximum effective total doses of 375 mg/kg and 250 mg/kg, respectively, on a model of a spontaneously metastasizing transferable tumor melanoma B16. Both compounds showed a high antimeta- static effect, more pronounced for the dialkyl organic compound.

Assessment of total annual effective doses to representative person, for authorised and accidental releases from the Nuclear Medicine Department at Cattinara Hospital (Trieste, Italy)

PurposeClinical procedures in a Nuclear Medicine Department produce radioactive liquid and solid waste. Regarding waste release into the environment from an authorised hospital, it is mandatory to verify the compliance with European Directive 2013/59/EURATOM, adopted by the Italian Government via the Legislative Decree 101/2020. MethodsDifferent activity release pathways into the environment from Trieste Nuclear Medicine Department have been analysed: liquid waste from patients’ excreta discharged by sewage treatment system into the sea, and atmospheric releases following solid waste incineration. Reference models, provided by NCRP and IAEA guidelines, have been implemented to assess the impact of the discharged radioactivity for coastal waters and atmospheric transport conditions. Finally, an accidental fire event occurring in Radiopharmacy Laboratories has been simulated by HotSpot software. ResultsAdvanced screening models give an effective dose to population of 5.3 · 10−3 µSv/y and 1.4 · 10−4 µSv/y for introduction by sewage system into coastal waters and atmospheric releases by the incinerator, respectively. Workers involved in the maintenance of the sewage treatment plant receive a total annual effective dose of 3.8 µSv/y, while for incinerator staff the total annual exposure is 5.9 · 10−8 µSv/y. For the accidental fire event the maximum total effective dose to an individual results 3.8 · 10−8 Sv with mild wind, and 4.1 · 10−7 Sv with strong wind. ConclusionsThe total annual effective doses estimated to representative person, due to both Nuclear Medicine authorised clinical practices and in case of an accidental fire event, are in compliance with regulatory stipulations provided by Directives.

UJI EFEKTIVITAS KRIM BUNGA KAMBOJA (PLUMERIA SP.) DALAM PENYEMBUHAN ULKUS KAKI DIABETIKUS

Introduction: Diabetes mellitus is a disease with a high number of cases. Complication of diabetes mellitus, such as diabetic foot ulcer, is rarely discussed. Treatment of diabetic foot ulcers often become a burden due to high cost, so a breakthrough is needed. Flavonoids have been reported to have benefits on wound healing. One of the plants that contain flavonoids is frangipani flower (Plumeria sp.).
 Methods: The cream made in 3 concentrations : 25%, 50%, and 75%. Cream was given to 24 rats that had been induced with alloxan. The cream will be given 2 times a day and the wound area is observed for 7 days. The rats will be euthanized and histological observations are made by hematoxylin preparations for collagen that will be analysis by ImageJ.
 Results: Wound closure and collagen area of the treated group better than the control group. The average wound closure of group I was 37.25%, group II was 75.75%, group III was 66.67%, and group IV was 61.70%. The average area of collagen in group I is 265776 pixels2, group II is 399579.5 pixels2, group III is 281749.75 pixels2, and group IV is 271382.9 pixels2.
 Discussion: The best result is group II. Increasing the dose of the cream didn’t give more significant effect so 25% dose was the maximum effective dose (MaxED). 
 Conclusion: The administration of frangipani flower extract cream (Plumeria sp.) effective for diabetic foot ulcers and the maximum effective dose was 25%. 
 Keywords: frangipani flower, diabetic foot ulcers, collagen, flavonoids

Abstract 1137: Determination of a recommended Phase 2 dose (RP2D) for SRF388, a first-in-class IL-27-blocking antibody, in patients with advanced solid tumors

Abstract SRF388 is a first-in-class, anti-IL-27 antibody developed to enhance immune responses within the tumor microenvironment. Preclinical studies have demonstrated that IL-27 pathway blockade can inhibit tumor growth in mouse models of liver cancer and lung cancer metastases. There is also evidence that IL-27 pathway inhibition is accompanied by activation of the innate and adaptive arms of the immune system. An ongoing Phase I trial has shown good tolerability at all dose levels tested and preliminary monotherapy antitumor activity with SRF388 (NCT04374877). Here, we describe the preclinical and clinical data used to select a RP2D and characterize cytokine and chemokine changes observed in patients after treatment with SRF388. To guide selection of the RP2D, the relationship between maximal effective dose (MaxED), pharmacokinetics (PK), and whole blood inhibition of IL-27-mediated phosphorylation of STAT1 by SRF388 was evaluated in a mouse model of liver cancer. The concentration of SRF388 associated with optimal antitumor activity was ~20-fold above the concentration needed for complete inhibition (> 90%) of whole blood phosphorylated STAT1 (pSTAT1). These PK and activity relationships were also defined in patients during the dose-escalation phase of the trial and integrated with safety and efficacy data to select a monotherapy RP2D. In patients, PK were linear, no dose-limiting toxicities were reported, complete pSTAT1 inhibition was achieved throughout the first cycle at 0.3 mg/kg, and 1 patient experienced a confirmed partial response per RECIST version 1.1 at a dose of 10 mg/kg. In the MaxED mouse model, the area under the concentration versus time curve (AUC) associated with significant antitumor activity was 1720 day*μg/mL. In patients, the corresponding target AUC was achieved clinically at 10 mg/kg after a single dose of SRF388. Changes in the concentration of several serum cytokines and chemokines were observed after SRF388 treatment including an increase in IL-27, a phenomenon described for other anti-cytokine antibodies due to altered clearance of the cytokine-antibody complex. Changes in a subset of other serum cytokines/chemokines correlated with a reduction in target lesion size. Taken together, these data support the selection of a monotherapy RP2D of 10 mg/kg intravenously every 4 weeks for SRF388. These data highlight how complementary strategies utilizing preclinical and clinical biomarker evaluations can be employed to establish a monotherapy RP2D and assess biological activity of a first-in-class anti-cytokine antibody, SRF388, for patients with cancer. Citation Format: Jonathan A. Hill, Kerry F. White, Matthew Rausch, Jou-Ku Chung, Amita Patnaik, Aung Naing, Daniel Morgensztern, Charlene M. Mantia, Nizar M. Tannir, Lon S. Smith, Beth Bowers, Alex Alika, Lauren C. Harshman, Benjamin H. Lee. Determination of a recommended Phase 2 dose (RP2D) for SRF388, a first-in-class IL-27-blocking antibody, in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1137.

Influx of radioactive gas in norm occurrences in Northeastern Brazil

Radon and progeny are potentially relevant in radioecological studies, as they contribute more than half of the exposure to environmental radiation. The investigation of 222Rn in internal environments of municipalities of Paraíba and Rio Grande do Norte in Brazil was carried out using passive dosimetry with α Espec-222, installed in environments selected by the history of natural radiative occurrences. The monitoring time was eight months to consider seasonal influence. Concentrations from 26.91 to 316.35 Bq m-3 were obtained, with a maximum effective dose of almost 8 mSv y-1. The influence on households exceeds, by almost 31%, the average obtained for occupational environments. The municipalities of Paraíba presented higher results for Rn, with an average of almost 176 Bq m-3 and an effective dose greater than 4 mSv y-1. The application of individual occupancy factors for home and work environments made it possible to combine the dosimetric models, making the scenario closer to the real exposure of individuals who work and reside in the same municipality, with a dosimetric response of 21.45% lower than the model used worldwide. The different scenarios applied allowed expanding the radiometry of the environments, generating a database that precedes studies of environmental and radioecological impacts, strengthening security and enabling new works to interpret public health problems in search of joint and shared solutions.

ESTABLISHING THE AVERAGE EFFECTIVE DOSE OF 2-HYDROXY-N-NAPHTHALENE-1-IL-2-(2-OXO-1,2-DIHYDRO-INDOL-3-YLIDENE)-ACETAMIDE AT THE «PUNISHABLE BEHAVIOR» MODEL

Derivatives of 2-oxoindoline demonstrate significant biological and pharmacological activity, including diuretic, anti-inflammatory, antitumor, antiviral, antibacterial, analgesic, sedative, anticonvulsant and other effects. The aim of this research is to establish the average effective dose of 2-hydroxy-n-naphthalene-1-yl-2-(2-oxo-1,2-dihydro-indol-3-ylidene)-acetamide (compound 18) as a potential anxiolytic, as well as its therapeutic index. Materials and methods of research. The experiments were performed on 36 albino adult male Wistar rats. The average effective dose (ED50) of compound 18 for anxiolytic activity was investigated in the «punishable behavior» test. Rats were divided into 6 groups of 6 animals each. The dose range for the intraperitoneal route of administration was (1, 3, 6; 12, 24, 48 mg/kg). Results and discussion. The «punishable behavior» model, Vogel variant, determined the average effective dose (ED50) and dose-response relationship for 2-hydroxy-n-naphthalene-1-yl-2-(2-oxo-1,2-dihydro-indol-3-ylidene)-acetamide (compound 18) with a single intraperitoneal injection. Analysis of the results shows that the maximum dose that did not cause the effect was 1.0 mg/kg, the minimum effective dose ED16 was 4.5 mg/kg, and the maximum effective dose ED100 was 48 mg/kg. Conclusion. Experimentally determined ED50 of compound 18 in rats when administered intraperitoneally in the «punishable behavior» test, variant Vogel, was 11.9±2.85 mg/kg. The ED50 confidence margins were (4.92÷18.9) mg/kg. According to the therapeutic index, substance 18 exceeds diazepam by 14.8 times.

The ENDS of assumptions: an online tool for the epistemic non-parametric drug-response scoring.

MotivationThe drug sensitivity analysis is often elucidated from drug dose–response curves. These curves capture the degree of cell viability (or inhibition) over a range of induced drugs, often with parametric assumptions that are rarely validated.ResultsWe present a class of non-parametric models for the curve fitting and scoring of drug dose–responses. To allow a more objective representation of the drug sensitivity, these epistemic models devoid of any parametric assumptions attached to the linear fit, allow the parallel indexing such as half-maximal inhibitory concentration and area under curve. Specifically, three non-parametric models including spline (npS), monotonic and Bayesian and the parametric logistic are implemented. Other indices including maximum effective dose and drug–response span gradient pertinent to the npS are also provided to facilitate the interpretation of the fit. The collection of these models is implemented in an online app, standing as useful resource for drug dose–response curve fitting and analysis.Availability and implementationThe ENDS is freely available online at https://irscope.shinyapps.io/ENDS/ and source codes can be obtained from https://github.com/AmiryousefiLab/ENDS.Supplementary information Supplementary data are available at Bioinformatics online.

Incorporation Monitoring of Staff using I-131 and Lu-177 in a Nuclear Medicine Ward

In addition to the well-established therapy with iodine-131, treatments with lutetium-177 are increasingly being performed on an inpatient basis in Germany. All of these treatments have be taken into account when assessing the potential internal dose and for incorporation monitoring of personnel. This article describes the experience with and the results of incorporation monitoring of staff of a nuclear medicine ward of a university hospital in Germany. Personnel working in a nuclear medicine ward was regularly measured using a whole body counter. In total, 234 measurements were performed over a period of 12 months. Incorporation factors were determined considering activities handled or applied to patients in the respective time period. In approx. 74 % of measurements, no incorporations was found. In the remaining measurements, activity was detected. Assuming incorporation, the maximum effective dose would be less than 0.15 mSv per measurement. The incorporation factors determined in this work were in the order of magnitude of 10-7 for all groups except for personnel performing radiochemical quality control. For this group, only an upper limit of the incorporation factor of 10-5 can be specified. The risk of incorporating radiactivity can be considered low for personnel working in a nuclear medicine ward. An incorporation factor of 10-7 is appropriate for medical, nursing, and cleaning staff and personnel performing radiochemical syntheses.

Effect of Hybrid Organotin Compound on Activity of LPO and Antioxidant Protection of the Liver Tissues in Animals with Melanoma B16.

The central element of the "metastatic organotropism" is a shift of the pro/antioxidant balance in cells and activation of oxidative stress and protective antioxidant systems. We studied the effects of bis(3,5-di-tert-butyl-4-hydroxyphenylthiolate)dimethylol (Me-3) in the maximum effective and toxic total doses on the level of markers of oxidative stress and antioxidant protection in the liver of mice with melanoma B16 before the appearance of macroscopic metastases. In 48 h after tumor inoculation, Me-3 was administered intraperitoneally once a day for 5 days in total doses of 375 and 500 mg/kg according to the classical method. Administration of the hybrid organotin compound Me-3 produced different effects on the pro/antioxidant state of the microenvironment of liver tissue as the target of melanoma B16 metastasis. The results suggest that inversion of the anti/prooxidant profile of Me-3 is determined by its dose.

Occupational radiation dose assessment for nuclear medicine workers in Turkey: A comprehensive investigation

ObjectiveRadioisotopes are used extensively in nuclear medicine. Analysis of occupational doses received by medical radiation workers, especially nuclear medicine staff dealing with radioisotopes, contributes significantlyto enhancing safe practice and promoting radiation protection measures in the radiology department. The current study aimed to determine the time trend and the differences in occupational radiation dose among nuclear medicine workers. MethodsReadings of 394 OSL dosimeters were obtained from 31 medical workers and grouped into five worker groups (technologist, physician, nurse, radio-pharmacist, and radio-physicist). ResultsThe average number of workers dropped to 4.5 in 2020 and 2021 compared to 14.4 in 2014 to 2019. The average annual effective dose and skin dose for all workers based on measurements for a typical yearly workload of 5000 patients were 1.21 (±1.15) mSv and 2.86 (±1.32) mSv, respectively. The highest average annual effective and skin dose was 5.41 and 5.82 mSv, respectively. The NM technologist working in PET/CT received higher mean and maximum effective and skin doses than the other worker groups. ConclusionThe annual effective and skin doses were below the national legislation and international standards. However, improvements in radiation protection practices could be implemented to reduce occupational radiation dose to NM technologists, the most exposed worker group in this study.

PD1 CD44 antiviral peptide as an inhibitor of the protein-protein interaction in dengue virus invasion

Dengue virus (DENV) infection is mediated by the interaction between the virus envelope protein and cellular receptors of the host cells. In this study, we designed peptides to inhibit protein-protein interaction between dengue virus and CD44 receptor, which is one of the receptors used by DENV for entry. In silico model complexes were designed between domain III of the viral envelope protein of dengue virus 2 and the domain of human CD44 receptor using ClusPro 2.0, (https://cluspro.bu.edu/login.php), and inhibition peptides were designed with Rosetta Online-Server(http://rosie.rosettacommons.org/peptiderive). We identified one linear antiviral peptide of 18 amino acids derived from the human CD44 receptor, PD1 CD44. It did not show hemolysis or toxicity in HepG2 or BHK cell lines, nor did it stimulate the release of IL-1β, IL-6, TNF-α, and IFN-γ, below 100 µM. It had an IC50 of 13.8 µM and maximum effective dose of 54.9 µM evaluated in BHK cells. The decrease in plaque-forming units/mL for DENV1, DENV2, DENV3, and DENV4 was 99.60%, 99.40%, 97.80%, and 70.50%, respectively, and similar results were obtained by RT-qPCR. Non-structural protein 1 release was decreased in pre- and co-treatment but not in post-treatment. Competition assays between the DN59 peptide, envelope protein, and the fragment of domain III "MDKLQLKGMSYSMCTGKF" of the viral envelope of DENV2 and PD1 CD44 showed that our peptide lost its antiviral activity. We demonstrated that our peptide decreased endosome formation, and we propose that it binds to the envelope protein of DENV, inhibiting viral invasion/fusion.

Monte Carlo evaluation of effective dose and risk of exposure induced cancer death (REID) for common examinations in stereo radiography (EOS) imaging: Considering age and gender

IntroductionThe aim of this study is to evaluate the effective dose and cancer risk of examinations in EOS imaging system in different age and gender groups. Materials and methodsIn total, 555 patients who had undergone common EOS imaging examinations were entered into the study. Exposure parameters and patients’ characteristics for lower limb, full spine and full body imaging techniques, at different gender and age groups, were evaluated. Finally, effective dose and risk of exposure induced cancer death (REID) was calculated with the Monte Carlo based PCXMC software. ResultsThe difference between average effective doses of male and female was not significant (p ≥ 0.05), however, the corresponding REID showed statistically significant difference (p ≤ 0.001). The average effective dose of patients (without considering technique, age and gender) was obtained as 0.13 mSv. The corresponding average REID was 8.84 per million. The maximum average effective dose value was obtained for patients over 10 years of age with the full body technique (0.17 ± 0.05 mSv). The maximum average REID value was obtained for full body technique and for patient with 0–10 years old (15.20 ± 10.00 per million). ConclusionIn common EOS imaging examinations, the effective dose and REID values of patients in both genders in all age groups are less than the corresponding values in other imaging modalities (according to previous studies). However, according to stochastic effects of ionizing radiation and based on the As Low As Reasonably Achievable (ALARA) principle, more considerations are necessary, especially in the full body technique and for female examinations.

Simulating the Potential Impacts of Nuclear Power Plant Accident for Northern Vietnam

The Fangchenggang nuclear power plant has been built very close to the Vietnam boundary. This is done to generate potential impacts for Northern Vietnam if nuclear power plant accident occurs. This study applied the Weather Research and Forecasting (WRF) model to construct the meteorological data at horizontal mesh resolution of 1 km as input for the FLEXible PARTicle dispersion model (FLEXPART). The assumption of the nuclear accident at Fangchenggang Power Plant is considered with setup parameter of the Fukushima accident. The results show a similar in simulating the 137Cs concentration from 03 out of 24 experiments configured with different parameterisation schemes of the WRF model. However, the dry and wet deposition of radioactive 137Cs are significantly different. It is especially illustrated that if the accident occurs, then almost all provinces in northern Vietnam are affected. The high concentration of radioactive pollutants may be intensively transported from Fangchenggang nuclear power plant to Vietnam under the domination of wind fields in the wintertime. The maximum values of the total effective dose rate could reach up to over 10 mSvh-1 of dose rate during 50 to 100 hours. Importantly, the maximum effective dose continues to be observed during 145 to 205 hours.

INVESTIGATION OF ENVIRONMENTAL RADIOACTIVITY AT A DECOMMISSIONED URANIUM MINE IN SOUTHERN CHINA.

An environmental radioactivity survey was performed on a uranium mine that has been decommissioned for >10 y. According to the characteristics of this uranium mine, the relevant parameters, such as the surface-absorbed dose rate in air, the radon and radon progeny concentrations in the air, the radon exhalation rate from the soil surface and the concentrations of natural radionuclides in soil and surface water, were measured. The results show that the maximum annual effective doses of residents and employees in the uranium mine caused by radon and radon progenies inhalation were 1.48 and 1.74mSv, respectively, and the maximum annual effective doses of residents and employees caused by gamma-ray external radiation were 1.16 and 1.32mSv, respectively.

Modelling of indoor external and internal exposure due to different building materials containing NORMs in the vicinity of a HNBRA in Mahallat, Iran

In this study, by considering the Naturally Occurring Radioactive Materials (NORMs) contained in the building materials used in Mahallat, Iran - an area exposed to a high level of natural background radiation - residential scenarios were simulated by applying the computer code RESRAD-BUILD to estimate the long-term Effective Dose rate of three different cases of basic building materials utilized in walls, floors and ceilings. Maximum effective dose rates of between 504 and 1433 μSv yr−1 were calculated in the second case study, tiled cement floor. The highest external and radon doses were also calculated to be 369 and 1064 μSv, respectively. The simulation results revealed that 232Th and 40K contribute the most and least to the indoor dose, respectively. As a result of a sensitivity analysis, it was found that the air exchange rate is a key variable to easily reduce the radiological impacts of building materials. It was also shown that due to the presence of 226Ra, the sensitivity of effective dose to changes in wall thickness was higher than other radionuclides found in the building materials.