Read by QxMD icon Read

Radiation and Environmental Biophysics

D V Ivanov, E A Shishkina, D I Osipov, V I Starichenko, S N Bayankin, M V Zhukovsky, E A Pryakhin
Otoliths are the organs which fish use for hearing and keeping balance. Otoliths are the most calcified tissues in the fish body. In contrast to bones, otoliths are not affected by remodeling and, therefore, they are expected to accumulate any dose from ionizing radiation during lifetime. Therefore, EPR dosimetry with fish otoliths could be an important tool for dose reconstruction in radiobiology and radioecology. It could also provide useful information remediation actions to de-contaminate waterbodies. Consequently, in the present study, otoliths of three contaminated fish species (roach (Rutilus rutilus), pike (Esox lucius) and perch (Perca Fluviatilis)) were examined with Electron Paramagnetic Resonance (EPR) spectroscopy...
October 15, 2018: Radiation and Environmental Biophysics
Mohammad Abuqbeitah, Mustafa Demir, İffet Çavdar, Handan Tanyildizi, Nami Yeyin, Lebriz Uslu-Beşli, Levent Kabasakal, Nazenin İpek Işıkcı, Kerim Sönmezoğlu
The aim of the present study was to review the available models developed for calculating red bone marrow dose in radioiodine therapy using clinical data. The study includes 18 patients (12 females and six males) with metastatic differentiated thyroid cancer. Radioiodine tracer of 73 ± 16 MBq 131 I was orally administered, followed by blood sampling (2 ml) and whole-body scans (WBSs) done at several time points (2, 6, 24, 48, 72, and ≥ 96 h). Red bone marrow dose was estimated using the OLINDA/EXM 1...
October 8, 2018: Radiation and Environmental Biophysics
Eder J Guidelli, Iara S Lima, Oswaldo Baffa
The risk of a radiation episode has increased in the last years due to several reasons. In case of a nuclear incident, as with the use of an improvised nuclear device, determination of the radiation doses received by the victims is of utmost importance to define the appropriate medical treatment or to monitor the late effects of radiation. Dose assessment in case of accidents can be performed using commonplace materials found in the accident area. In this paper, the dosimetric properties of monosodium glutamate are investigated by electron spin resonance spectroscopy (ESR), for retrospective and accidental dosimetry...
September 21, 2018: Radiation and Environmental Biophysics
Serine Sarra Bouacid, Fayçal Kharfi, Fouad Boulakhssaim
In this work, dose measurements were performed to evaluate an external radiotherapy treatment plan and, particularly, to validate dose calculations for a lung lesion case. Doses were calculated by the Varian Eclipse treatment planning system using the AAA anisotropic analytical algorithm. The measurements were performed using a Rando anthropomorphic phantom and TLD700 thermoluminescent dosimeters. The comparison between doses calculated and doses measured by means of thermoluminescence (TL) shows compatibility except for a few points, due to the limitations in the heterogeneity correction used for the case studied here...
September 11, 2018: Radiation and Environmental Biophysics
Ali Neshastehriz, Zohreh Khosravi, Habib Ghaznavi, Ali Shakeri-Zadeh
Recently, gold-coated iron oxide nanoparticles (Au@IONPs) have received a great deal of attention in cancer therapy. In this in vitro study we aimed to investigate the anti-cancer effects of Au@IONPs core-shell nanoparticles when applied in thermo-radiotherapy. Moreover, we investigated the level of apoptosis induced in U87-MG human glioma cells after receiving a combinatorial treatment regimen (Au@IONPs + hyperthermia + radiotherapy). Firstly, the Au@IONPs nanocomplex was prepared and characterized...
September 10, 2018: Radiation and Environmental Biophysics
Uwe Schneider, Linda Walsh, Wayne Newhauser
Obtaining a correct dose-response relationship for radiation-induced cancer after radiotherapy presents a major challenge for epidemiological studies. The purpose of this paper is to gain a better understanding of the associated uncertainties. To accomplish this goal, some aspects of an epidemiological study on breast cancer following radiotherapy of Hodgkin's disease were simulated with Monte Carlo methods. It is demonstrated that although the doses to the breast volume are calculated by one treatment plan, the locations and sizes of the induced secondary breast tumours can be simulated and, based on these simulated locations and sizes, the absorbed doses at the site of tumour incidence can also be simulated...
August 31, 2018: Radiation and Environmental Biophysics
K Bales, S Dewji, E Sanchez
Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present work, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields...
August 23, 2018: Radiation and Environmental Biophysics
G M Kendall, P Chernyavskiy, J D Appleton, J C H Miles, R Wakeford, M Athanson, T J Vincent, N P McColl, M P Little
Gamma radiation from naturally occurring sources (including directly ionizing cosmic-rays) is a major component of background radiation. An understanding of the magnitude and variation of doses from these sources is important, and the ability to predict them is required for epidemiological studies. In the present paper, indoor measurements of naturally occurring gamma-rays at representative locations in Great Britain are summarized. It is shown that, although the individual measurement data appear unimodal, the distribution of gamma-ray dose-rates when averaged over relatively small areas, which probably better represents the underlying distribution with inter-house variation reduced, appears bimodal...
August 21, 2018: Radiation and Environmental Biophysics
Vladimir Spielmann, Wei Bo Li, Maria Zankl
Internal dosimetry after incorporation of radionuclides requires standardized biokinetic and dosimetric models. The aim of the present work was to identify the parameters and the components of the models which contribute most to dosimetric uncertainty. For this a method was developed allowing for the calculation of the uncertainties of the absorbed dose coefficients. More specifically, the sampling-based regression method and the variance-based method were used to develop and apply a global method of sensitivity analysis...
August 2018: Radiation and Environmental Biophysics
Rowida Abdalla, Amr Omar, Kareem Eid
The purpose of this study was to evaluate the ability of radiographic densitometry in detecting the early demineralization of human enamel and cementum in irradiated and non-irradiated teeth. Sixty extracted teeth were divided into two groups: irradiated group and non-irradiated group. After irradiation, the groups were subjected to demineralization-remineralization (PH) cycling. Radiographic densitometric measurements (gray values) of a selected area of interest in the enamel and in the cementum of each tooth were performed at baseline and after PH cycling...
August 2018: Radiation and Environmental Biophysics
Iwona Słonecka, Krzysztof Łukasik, Krzysztof W Fornalski
The present paper proposes two methods of calculating components of the dose absorbed by the human body after exposure to a mixed neutron and gamma radiation field. The article presents a novel approach to replace the common iterative method in its analytical form, thus reducing the calculation time. It also shows a possibility of estimating the neutron and gamma doses when their ratio in a mixed beam is not precisely known.
August 2018: Radiation and Environmental Biophysics
Esmail Jafari, Mehrosadat Alavi, Fatemeh Zal
The goal of this study was to evaluate the protective and mitigative effect of vitamin C on oxidative stress in differentiated thyroid cancer (DTC) patients ablated with radioiodine. 58 DTC patients selected for radioactive iodine therapy (RAIT) with 5550 MBq 131 Iodine were divided into four groups. Group 1 (control group) consisted of patients who underwent RAIT routinely. Other patients received 1500 mg vitamin C daily 2 days after (group 2), 2 days before to 2 days after (group 3) and 2 days before RAIT (group 4)...
August 2018: Radiation and Environmental Biophysics
Simon P Keam, Twishi Gulati, Cristina Gamell, Franco Caramia, Gisela Mir Arnau, Cheng Huang, Ralf B Schittenhelm, Oded Kleifeld, Paul J Neeson, Scott G Williams, Ygal Haupt
Transcriptional dosimetry is an emergent field of radiobiology aimed at developing robust methods for detecting and quantifying absorbed doses using radiation-induced fluctuations in gene expression. A combination of RNA sequencing, array-based and quantitative PCR transcriptomics in cellular, murine and various ex vivo human models has led to a comprehensive description of a fundamental set of genes with demonstrable dosimetric qualities. However, these are yet to be validated in human tissue due to the scarcity of in situ-irradiated source material...
August 2018: Radiation and Environmental Biophysics
Kentaro Ariyoshi, Tomisato Miura, Kosuke Kasai, Nakata Akifumi, Yohei Fujishima, Mitsuaki A Yoshida
Although evidence suggests that ionizing radiation can induce the bystander effect (radiation-induced bystander effect: RIBE) in cultured cells or mouse models, it is unclear whether the effect occurs in cells of wild animals. We investigated medium-mediated bystander micronucleus (MN) formation and DNA damage in un-irradiated cells from a large Japanese field mouse (Apodemus speciosus). We isolated four clones of A. speciosus embryonic fibroblasts (A603-1, A603-2, A603-3, and A603-4) derived from the same mother, and examined their radiation sensitivity using the colony-forming assay...
August 2018: Radiation and Environmental Biophysics
Xue-Lei Tian, Xue Lu, Jiang-Bin Feng, Tian-Jing Cai, Shuang Li, Mei Tian, Qing-Jie Liu
Chromosome damage is related to DNA damage and erroneous repair. It can cause cell dysfunction and ultimately induce carcinogenesis. Histone acetylation is crucial for regulating chromatin structure and DNA damage repair. Ionizing radiation (IR) can alter histone acetylation. However, variations in histone acetylation in response to IR exposure and the relationship between histone acetylation and IR-induced chromosome damage remains unclear. Hence, this study investigated the variation in the total acetylation levels of H3 and H4 in human lymphocytes exposed to 0-2 Gy 60 Co γ-rays...
August 2018: Radiation and Environmental Biophysics
Roula Ajrouche, Candice Roudier, Enora Cléro, Géraldine Ielsch, Didier Gay, Jérôme Guillevic, Claire Marant Micallef, Blandine Vacquier, Alain Le Tertre, Dominique Laurier
Radon is the second leading cause of lung cancer after smoking. Since the previous quantitative risk assessment of indoor radon conducted in France, input data have changed such as, estimates of indoor radon concentrations, lung cancer rates and the prevalence of tobacco consumption. The aim of this work was to update the risk assessment of lung cancer mortality attributable to indoor radon in France using recent risk models and data, improving the consideration of smoking, and providing results at a fine geographical scale...
August 2018: Radiation and Environmental Biophysics
P Vivek Vardhan, Lata Israni Shukla
The present article focuses on the influence of gamma irradiation and post-irradiation storage conditions on FT-IR spectra of 1 mm thick polystyrene irradiated with 51, 77 and 129 kGy. The increase in amplitude corresponding to 3600, 3400 and 2100 cm- 1 stretching frequencies clearly showing the formation of O-H and C=O bonds (~ 25%). On prolonged storage (2160 h) in the dark, there is an increase in O-H group (~ 28%). The electron cloud facilitates the formation of hydroxyl group in irradiated polystyrene...
August 2018: Radiation and Environmental Biophysics
Ewa M Nowosielska, Aneta Cheda, Robert Zdanowski, Sławomir Lewicki, Bobby R Scott, Marek K Janiak
Tritium is a potentially significant source of internal radiation exposure which, at high levels, can be carcinogenic. We evaluated whether single intraperitoneal injection of BALB/c and C57BL/6 mice with tritiated water (HTO) leading to exposure to low (0.01 or 0.1 Gy) and intermediate (1.0 Gy) cumulative whole-body doses of β radiation is immunosuppressive, as judged by enhancement of artificial tumour metastases, functioning of NK lymphocytes and macrophages, circulating cytokine's levels, and numbers of bone marrow, spleen, and peripheral blood cells...
August 2018: Radiation and Environmental Biophysics
Atiyeh Ebrahimi-Khankook, Alireza Vejdani-Noghreiyan
Nowadays, Monte Carlo calculations are commonly used for the evaluation of dose distributions and dose volume histograms in eye brachytherapy. However, currently available eye models have simple geometries, and main substructures of the eye are either not defined in details or not distinguished at all. In this work absorbed doses of eye substructures have been estimated for eye plaque brachytherapy using the most realistic eye model available, and compared with absorbed doses obtained with other available eye models...
June 7, 2018: Radiation and Environmental Biophysics
Branko Petrinec, Marina Poje Sovilj, Dinko Babić, Tomislav Meštrović, Igor Miklavčić, Vanja Radolić, Denis Stanić, Branko Vuković, Marko Šoštarić
A study of the environmental radioactivity in the Kopački Rit Nature Park, Croatia, is presented. This wildlife reserve is part of the Middle Danube River Basin, and it is exposed to various pollutants due to a number of human activities in the surroundings, where there is a nuclear power plant and also urban centres and areas of intense agricultural production. Results for the activity concentrations of soil and surface water samples do not indicate any elevated radioactivity level, which is confirmed by on-site measurements of ambient dose rate equivalent...
June 5, 2018: Radiation and Environmental Biophysics
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"