Dissertations / Theses: 'Radiation Biological Effects'

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Chahal, Singh. "Biological effects of tarahertz radiation." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493749.

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This thesis is an investigation of the biological effects of terahertz (THz) radiation at non-thermal power levels. One may loosely define the THz region of the electromagnetic spectrum spanning a range of frequencies between 0.1 and 10 THz. Recent advances in methods of generation and detection have made it possible to build instruments and perform experiments in this relatively unexplored part of he spectrum. Water represents an important constituent of biological systems and strongly absorbs in this frequency range. As a consequence, irradiation at THz frequencies can raise the temperature of biological material and temperature dependent processes can be influenced. THz radiation is non-ionising, with associated photon energies close to the thermal energy level of a metabolically active biological entity. At low power levels, however, a non-linear bio-effect relating to energy transfer from the field to the organism, which is not associated with a temperature rise, may be observed at specific frequencies. The current understanding of the interaction between THz radiation and biological material is. therefore, discussed within the framework of dielectric theory and is considered at both the macroscopic and microscopic levels. A discussion of important biological molecules, cells, tissues and a range of cellular processes is developed within this framework and the complexity of an interaction within a biological system is defined.

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Seddon, Gavin M. "Radiation effects on biochemical systems." Thesis, University of Salford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313912.

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Gricienė, Birutė. "Cytogenetic effects of low ionising radiation doses and biological dosimetry." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101223_153129-29353.

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The intensive use of ionising radiation (IR) sources and development of IR technology is related to increased exposure and adverse health risk to workers and public. The unstable chromosome aberration analysis in the group of nuclear energy workers (N=84) has shown that doses below annual dose limit (50 mSv) can induce chromosome aberrations in human peripheral blood lymphocytes. Significantly higher frequencies of the total chromosome aberrations were determened in the study group when compared to the controls ((N=82). The risks were found to differ with the type of activities and occupational exposure. Activities related to internal and neutron exposure risk may be regarded as potentially more dangerous when compared to other activities related with external gamma exposure doses only. The impact of age and smoking to chromosome aberration frequency was found to be insignificant. The results of this study show that cytogenetic monitoring can be used for IR occupational exposure risk assessment for different occupational groups of radiation workers and may provide additional information to ensure and optimise the radiation protection of radiation workers. The gamma radiation (60Co) dose-response curves for chromosome aberrations in vitro were established in Lithuania for the first time. Application of the established dose-response curves enables to perform the biological dosimetry in the country, to assess the doses of the first responders and people accidentally exposed to... [to full text]
Įvairiais tikslais naudojant jonizuojančiosios spinduliuotės (JS) šaltinius, darbuotojai ir gyventojai patiria JS apšvitą, kurią lydi neigiamo poveikio organizmui rizika. Taikant nestabilių chromosomų aberacijų analizės metodiką buvo nustatyta, kad ir mažos, neviršijančios darbuotojams nustatytų ribų (50 mSv), JS dozės gali iššaukti chromosomų pažaidas žmogaus limfocituose. Branduolinės energetikos srityje dirbančių asmenų grupėjė (N=84) nustatytas patikimai didesnis, palyginti su kontroline grupe (N=82), chromosomų pažaidų dažnis, įvertinta chromosomų pažaidų dažnio priklausomybė nuo jonizuojančiosios spinduliuotės ir apšvitos tipo. Konstatuota, kad veikla, susijusi su vidine ir neutronų apšvita, gali būti laikoma potencialiai pavojingesne bei sąlygojančia didesnę chromosomų pažaidų indukcijos riziką nei veikla, susijusi tik su išorinės gama spinduliuotės apšvita. Rūkymo ir amžiaus įtakos chromosomų aberacijų dažniui nenustatyta. Gauti tyrimo rezultatai rodo, kad citogenetinis monitoringas gali būti taikomas atskirų darbuotojų grupių JS apšvitos rizikos vertinimui bei suteikia papildomos informacijos užtikrinant ir optimizuojant darbuotojų radiacinę saugą. Šio darbo metu sudarytos gama spinduliuotės (60Co) kalibracinės dozės-atsako kreivės leidžia Lietuvoje atlikti biologinį dozių įvertinimą radiacinės avarijos metu nukentėjusiems ir dideles JS dozes gavusiems asmenis, kas svarbu tinkamai parenkant gydymo metodus. Taip pat bus galima papildomai įvertinti darbuotojo... [toliau žr. visą tekstą]

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Le, Roux Jacques. "The analysis of radiation-induced micronuclei in peripheral blood lymphocytes for purpose of biological dosimetry." Master's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/27038.

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In the investigation of radiation accidents, it is of great importance to estimate the dose absorbed by exposed persons in order to plan their therapy. Although occasionally in these situations physical dose measurements are possible, most often biological methods are required for dose estimation. The aim of this investigation was to assess the suitability of the cytokinesis blocked (CB) micronucleus assay as a biodosimetric method using lymphocytes irradiated in vivo. The approach adopted to achieve this was to estimate whole body doses by relating micronuclei yields in patients undergoing radiotherapy treatment with an in vitro radiation dose-response curve. These biologically derived estimates were then compared with the corresponding doses obtained by physical measurement and calculation. As a first approach a study was performed of the in vitro dose-response of gamma-ray induced micronuclei following cytokinesis-block in the lymphocytes of peripheral blood samples obtained from 4 healthy donors. The results indicated that the distribution of the induced micronuclei were overdispersed. Furthermore, a linear dose-response relationship was established when a curve was fitted to the data by an iteratively reweighted least squares method. By means of an analysis of covariance it was demonstrated that this result is in agreement with the dose-response relationships found by various other workers (Fenech et al., 1985; Fenech et al., 1986; Fenech et al., 1989; Balasem et al., 1992, and Slabbert, 1993). To assess the suitability and accuracy of dose assessment using the CB micronucleus assay for in vivo exposure of lymphocytes, blood samples obtained from 8 patients undergoing radiotherapy before, during and after treatment were examined. The physical doses of these patients were determined according to conventional radiation treatment plans and cumulative dose-volume histograms. The dose-volume histograms permitted calculation of integral doses and subsequently the estimate of equivalent whole-body doses. The results of the CB micronucleus assay applied to peripheral blood lymphocytes of 6 patients undergoing fractionated partial-body irradiation showed a dose-related increase in micronucleus frequency in each of the patients studied. This demonstrated that micronuclei analysis may serve as a quantitative biological measure of such exposures. The pooled data of these patients compared to the pooled data of the healthy donors show that there was no statistically significant difference between in vitro and in vivo results, however a slightly lower induced micronuclei frequency was observed after in vivo exposure. When the biological dose estimates for equivalent whole-body doses obtained from the in vitro dose response curve were compared with calculated physical doses, it was found that: biologically estimated dose = 0.936 physical dose. However, there was inadequate statistical evidence to discard the hypothesis that the gradient of the equation was equal to one. Therefore, the analysis of micronuclei induced in lymphocytes in vivo yields highly quantitative information on the equivalent whole-body dose. The negative binomial method was used for analysing the micronucleus data from two patients who received single, relatively larger tumour doses of 10 Gy each, with the objective to obtain estimates of the exposed body fraction and the dose to this fraction. The dose estimates to the irradiated volume were found to be within 30% of the physical tumour dose. The irradiated volume estimates seemed to be higher than the physically calculated volumes but by discarding the correction for the loss of cells due to interphase death the agreement was good between the physically and biologically determined integral doses. This study has revealed that the CB micronucleus assay appears to offer a reliable, consistent and relatively rapid biological method of whole body dose estimation. It is recognised that further corroborative work using the techniques described in this thesis is required for estimating localized exposure.

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Cantor, D. J. "The definition of radiobiology : The Medical Research Council's support for research into biological effects of radiation in Britain, 1919-1939." Thesis, Lancaster University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384316.

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This thesis is concerned with the definition of radiobiology by the Medical Research Council (MRC), the state financed medical research funding organisation, in inter-war Britain. It argues that radiobiology was largely .. defined as a specialty by struggles in surrounding fields - particularily radiology, clinical research and the bio-medical sciences. Groups within each of these fields turned to experimental research into the biological effects of radiation to further their attempts to secure an autonomous professional space within medicine, often against resistance from the leaders of medical practice. The MRC was crucial to these attempts, as it provided the first and major systematic research programme into the medical uses and biological effects of radiation during the inter-war years. However, I argue, experimental research was generally subverted to clinical objectives. Indeed, experimentalists themselves were uneasy about clinical domination of their research. However, they were farced into alliance with clinicians partly because they required a medical justification for using the Council's small supply of radium, and partly because the Council's independence in medical research was threatened by the leaders of medical practice. If the Council was not the ideal place to foster experimental research free from clinical interference, the clinicians who dominated it were also opposed to the control of research by the leaders of medical practice, and were generally mare sympathetic towards the bio-medical sciences. Con~equentlYI mast experimental scient~sts sided with these clinicians in order. to protect the Council's independence. Radiobiology reflected the accomodations each side had to make in this alliance.

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Zackrisson, Björn. "Biological effects of high energy radiation and ultra high dose rates." Doctoral thesis, Umeå universitet, Onkologisk radiobiologi, 1991. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96889.

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Recently a powerful electron accelerator, 50 MeV race-track microtron, has been taken into clinical use. This gives the opportunity to treat patients with higher x-ray and electron energies than before. Furthermore, treatments can be performed were the entire fractional dose can be delivered in parts of a second. The relative biological effectiveness (RBE) of high energy photons (up to 50 MV) was studied in vitro and in vivo. Oxygen enhancement ratio (OER) of 50 MV photons and RBE of 50 MeV electrons were investigated in vitro. Single-fraction experiments, in vitro, using V-79 Chinese hamster fibroblasts showed an RBE for 50 MV x-rays of approximately 1.1 at surviving fraction 0.01, with reference to the response to 4 MV x- rays. No significant difference in OER could be demonstrated. Fractionation experiments were carried out to establish the RBE at the clinically relevant dose level, 2 Gy. The RBE calculated for the 2 Gy/fraction experiments was 1.17. The RBEs for 20 MV x-rays and 50 MeV electrons were equal to one. In order to investigate the validity of these results, the jejunal crypt microcolony assay in mice was used to determine the RBE of 50 MV x-rays. The RBE for 50 MV x-rays in this case was estimated to be 1.06 at crypt surviving fraction 0.1. Photonuclear processes are proposed as one possible explanation to the higher RBE for 50 MV x-rays. Several studies of biological response to ionizing radiation of high absorbed dose rates have been performed, often with conflicting results. With the aim of investigating whether a difference in effect between irradiation at high dose rates and at conventional dose rates could be verified, pulsed 50 MeV electrons from a clinical accelerator were used for experiments with ultra high dose rates (mean dose rate: 3.8 x 10^ Gy/s) in comparison to conventional (mean dose rate: 9.6 x 10"^ Gy/s). V-79 cells were irradiated in vitro under both oxic and anoxic conditions. No significant difference in relative biological effectiveness (RBE) or oxygen enhancement ratio (OER) was observed for ultra high dose rates compared to conventional dose rates. A central issue in clinical radiobiological research is the prediction of responses to different radiation qualities. The choice of cell survival and dose response model greatly influences the results. In this context the relationship between theory and model is emphasized. Generally, the interpretations of experimental data are dependent on the model. Cell survival models are systematized with respect to their relations to radiobiological theories of cell kill. The growing knowledge of biological, physical, and chemical mechanisms is reflected in the formulation of new models. This study shows that recent modelling has been more oriented towards the stochastic fluctuations connected to radiation energy deposition. This implies that the traditional cell survival models ought to be complemented by models of stochastic energy deposition processes at the intracellular level.

S. 1-44: sammanfattning, s. 47-130: 5 uppsatser

digitalisering@umu

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Park, Young C. (Young Chul) 1960. "A Study of Some Biological Effects of Non-Ionizing Electromagnetic Radiation." Thesis, University of North Texas, 1996. https://digital.library.unt.edu/ark:/67531/metadc278105/.

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The experimental studies of this work were done using a microwave cavity spectrometer, Escherichia coli (E-coli) bacteria, and other peripheral equipment. The experiment consists of two steps. First, a general survey of frequencies from 8 GHz to 12 GHz was made. Second, a detailed experiment for specific frequencies selected from the first survey were further studied. Interesting frequency dependent results, such as unusually higher growing or killing rates of E-coli at some frequencies, were found. It is also concluded that some results are genetic, that is, the 2nd, and 3rd subcultures showed the same growing status as the 1st cultures.

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GARCIA, MARCIA A. A. "caracterizacao radioquimica e impacto radiologico ambiental no processamento de cassiterita para producao de estanho e chumbo metalicos." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9389.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Cleary, Helen Julia. "Genetic analyses of radiation-induced leukaemias/lymphomas." Thesis, Brunel University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324649.

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Starrs, Sharon Margaret. "Molecular mechanisms of DNA photodamage." Thesis, Queen's University Belfast, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314222.

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Fuller, Neil. "The biological effects of ionising radiation on crustaceans : combining lab and field studies." Thesis, University of Portsmouth, 2018. https://researchportal.port.ac.uk/portal/en/theses/the-biological-effects-of-ionising-radiation-on-crustaceans(ac55fd55-bfa4-44b2-ac1a-5b1bb1fe6f13).html.

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Amid a renewal of interest in the use of nuclear power and concern regarding past and potential nuclear incidents, assessing the impacts of radiation on the environment has emerged as an area of international scientific and regulatory concern. At present, the impacts of chronic low-dose radiation on non-human organisms are poorly understood. Crustaceans are internationally important model organisms in the field of radioecology and are of commercial and ecological importance. Consequently, this study aimed to adopt a combined laboratory and field approach to assessing the impacts of radiation on crustaceans. Both marine and freshwater crustaceans were exposed to environmentally relevant doses of beta radiation in the laboratory and a range of endpoints including male fertility, DNA damage and development were monitored. In addition, crustacean samples were collected from contaminated environments at Chernobyl and Fukushima and effects on development, reproduction and genetic diversity were assessed. In the laboratory, significant effects on male fertility and sperm DNA damage of the marine crustacean, Echinogammarus marinus, were recorded at doses of 1 mGy/d, with some evidence for knock-on impacts on female reproduction at lower doses of 0.1 mGy/d. No significant effects on male fertility were recorded in the freshwater crustacean, Gammarus pulex. No significant effects on reproduction, development or genetic diversity of crustaceans Asellus aqauticus and Eriocheir japonica (development only) were recorded at Chernobyl and Fukushima respectively. Laboratory studies suggest effects at dose levels below those proposed for environmental radioprotection, though the population-level consequences of these effects are unclear. Conversely, field studies of crustaceans at both Chernobyl and Fukushima found no significant effects of chronic radiation exposure. Based on these results, laboratory studies may provide overly conservative risk assessments of radiation impacts in the environment. These findings challenge current understanding in radioecology and will aid in assessing the risk posed by radiation to aquatic biota and the management of contaminated environments.

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KOSMISKAS, LUIS O. C. "Análise mecânica de réguas ósseas esterilizadas por radiação gama para uso em bancos de tecidos." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11502.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Dunne, Amanda Louise. "Cytotoxic effects of radiation and docetaxel in human tumour cells." Thesis, University of Ulster, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342410.

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CAPRONI, PRISCILA. "Acao da Bothrospstoxina-1 do veneno total de Bothrops jararacussu irradiados sobre o sistema imune." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11518.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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BARROS, ADILSON C. de. "Efeitos das ondas acústicas em pupas de Ceratitis capitada. (Wied., 1824)(Diptera:Tephritidae)." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11620.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

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DUARTE, CELINA L. "Estudo das medidas terapeuticas para reducao da contaminacao interna por radionuclideos." reponame:Repositório Institucional do IPEN, 1992. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10290.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Blood, Alan Physics Faculty of Science UNSW. "Biological effects of GSM mobile phone microwave radiation: an investigation of gene expression." Awarded by:University of New South Wales. School of Physics, 2005. http://handle.unsw.edu.au/1959.4/22071.

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There is evidence that athermal radiofrequency radiation can alter Heat Shock Protein (HSP) expression or protein phosphorylation, or alter MAP kinase signalling. Effects of long-term exposure in brain tissue due to repeated HSP perturbation (eg an inhibition of apoptosis) have been hypothesised (French et al, 2001). This study aimed to investigate the RNA expression profile (12,000 genes) and HSP family protein expression levels after either acute 1-hour or chronic 4-day intermittent exposures to simulated GSM radiation in a human primary fibroblast model. The results found minimal or no effects of GSM. Flasks were exposed to 900 MHz (217 Hz modulation) at 0.18 W/kg SAR within a Transverse Electromagnetic Mode chamber (TEM cell). Cultures rested for 2 hours before exposures. Affymetrix U95A microarray analysis of a single pilot set of experiments showed that about 40 genes were reported as upregulated >=2.5 fold in each condition. There was no evidence of altered expression of any MAPK-associated genes. Target genes reported in both conditions (CBFA2T1, ZNF148, ITGA1), and genes altered in one condition (CCS, PLEC1, BIRC5), and marginally altered HSP72 were selected for PCR analysis. No other members of the HSP family were altered. In three replicate experiments assayed by real-time PCR, six genes were either unchanged or showed randomly variable expression. However HSP72 RNA showed possible consistent slight upregulation of 1.37 +/- 0.21 in the chronic condition. Western immunoblots of HSP-60, -70, -72 and -V90 proteins showed no significant changes 5 hours after exposure. In preliminary studies using a serum starvation protocol, ERK-1 phosphorylation was unaltered after 5 or 30 minutes GSM (single experiments). When flasks were transiently cooled, ERK-1 phosphorylation was increased 20 minutes later, indicating a source of artefact in some protocols. An inflammatory challenge experiment with a low-dose of the cytokine IL-1???? found that acute GSM exposure post-challenge inhibited NF????B-mediated GRO???? induction by 1.5 fold (2 experiments). Preconditioning with mild heat induces transient inhibition of both NF????B signalling and apoptosis. Other studies indicate that EMF exposures similarly evoke cytoprotection. It is suggested that GSM evoked cytoprotective signalling in this inflammatory model.

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Dawe, Adam Sean. "Investigation of the biological effects of radiofrequency radiation using the nematode caenorhabditis elegans." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415627.

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Davidson, Matthew Allen. "Irradiators for measuring the biological effects of low dose-rate ionizing radiation fields." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/76941.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references.
Biological response to ionizing radiation differs with radiation field. Particle type, energy spectrum, and dose-rate all affect biological response per unit dose. This thesis describes methods of spectral analysis, dosimetry, biological assays, and mathematical modeling for determining the relative biological response for low dose-rate fields. The spatial dimensions of optically stimulated luminescence dosimeters make them ideal for measuring dose at a specific location. However the response of these dosimeters varies with photon energy. A method is presented for measuring dose delivered by several fields with photon energies less than 60 keV using these optically-stimulated luminescence dosimeters. This method is confirmed using an ion chamber dosimeter and computer simulation. The construction of 24Am irradiators for tissue culture and animal experiments using this dosimetry method is also described. The results of tissue culture experiments performed using these irradiators are presented, and the relative biological effectiveness (RBE) is determined for two fields with approximately equal dose-rates produced by shielding 24Am foil sources with aluminum and polyethylene. Biological effects can result from single instances of energy deposition within a cell or from the combination of separate instances, but at low dose-rates biological repair mechanisms reduce the probability of effects resulting from the combination of separate instances. At a sufficiently low dose-rate the effects due to combination of separate instances are negligible. A model of low dose-rate energy deposition within a cell nucleus was developed to determine this doserate. In this model the proportion of biological effects due to single instances of energy deposition within a cell nucleus is described in terms of the DNA repair rate of the biological 'system and the dose-rate and lineal energy transfer of the radiation field. This model also describes the projection of RBE values for fields with dose-rates below this threshold.
by Matthew Allen Davidson.
S.M.

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GIRAUDO, MARTINA. "Passive shielding of space radiation for human exploration missions - Simulations and Radiation Tests." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2711122.

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Space radiation is one of the main showstoppers for human exploration of deep space. When leaving the protection provided by Earth’s atmosphere and magnetic field, the astronaut crew find themselves immersed into a complex radiation field, originated by the interaction of different high-energy radiation sources with the spacecraft’s walls, and characterized by many particle species with a broad range of energies. The biological effects of the long-term radiation exposure is largely uncertain and could give rise not only to late solid cancers and leukemia, but also to early effects to cardiac and nervous tissues, possibly undermining mission success. An available countermeasure to defend the astronauts from radiation is passive shielding, i.e. the interposition of shielding materials between the radiation sources and the exposed subjects. However, the majority of space radiation is practically impossible to completely stop: the high energetic particles constituting the space environment have the capability to penetrate several meters of materials, generating a harmful component of secondary particles, further contributing to the radiation dose. The ability of a material to attenuate the incoming space radiation and the nature of the generated secondary particles largely depends on the traversed material itself, in particular on the ratio between its charge and mass atomic numbers, Z/A. The lower is this ratio, the higher the material’s capability to attenuate the incoming radiation will be, both through electromagnetic and nuclear interactions. While the radiobiology community is focusing on the biological effects, radiation physics is trying to lower uncertainties characterizing the radiation interactions with materials, performing radiation measurements of various nature. In this framework I focused my PhD activity on the study of materials which could be used in space as shielding layers and multipurpose structures have been evaluated and selected under different criteria. At first, their ability to shield different kinds of space radiation were calculated with the aid of 1D Monte Carlo simulations, also followed by an evaluation of their structural and thermal proprieties, cost, availability and compatibility with the space environment. Simulations, in particular, were performed both to support the material selection process both to produce guidelines for design. The selected materials were then procured to be tested under different radiation beams and different set-ups, in single and multi-layers configurations, in an attempt to reproduce space exposure conditions. At the same time, the radiation tests have been reproduced by means of Monte Carlo simulations, to compare the experimental results and the simulations’ outputs, confirming the codes’ ability to reproduce radiation measurements involving High Z-number and high Energy (HZE) particles. For some materials, suggestions were provided on which nuclear model was better reproducing the data. The performed experimental campaign suggested that a candidate shielding material suitable for Galactic Cosmic Rays (GCR) should be tested with at least two beams with different characteristics, since the results indicated that some materials good at shielding 972 MeV/nuc 56Fe ions performed very poorly when irradiated with high energetic alphas. Furthermore, among the material types included in this investigation work, Lithium Hydride resulted the best option to stop space radiation, when only radiation shielding properties are considered. At the end of the experimental campaigns, on the basis of the test results, a 3D simulation activity has started and is still on-going and a modular space habitat model has been created. Monte Carlo simulations have been carried out, reproducing different Moon exposure scenarios with the goal of calculating crew radiation exposure during a Moon surface mission. This work reports results only for a standard aluminum habitat, with only Moon soil used as shielding material. However, future simulations will include Lithium Hydride and possibly others materials as shielding layers, to evaluate their effectiveness in reducing the dose in a realistic exposure scenario. Preliminary results show that even with a heavily shielded spacecraft (the habitat taken in consideration in this work is providing from every direction at least 30 g/cm2 of aluminum equivalent) radiation exposure approaches values close to the existing annual radiation exposure limits. Part of this thesis’ work was done at Thales Alenia Space, using Thales Alenia Space infrastructures and in the framework of the ROSSINI2 study. The ROSSINI2 study has been supported by European Space Agency (ESA) under the contract RFP IPLPTE/LF/mo/942.2014 and with the generous support of NASA and BNL, providing beam time at the NSRL facility.

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GUARNIERI, MIRIAM C. "Estudo dos efeitos da radiacao gama de Co-60 nas propriedades bioquimicas, biologicas e imunologicas do veneno de Bothrops jararaca." reponame:Repositório Institucional do IPEN, 1992. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10291.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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22

Darkhshan, Fatemeh. "Mapping of murine radiation-induced acute myeloid leukaemia susceptibility loci." Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367693.

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GUILHEN, SABINE N. "Validacao de metodologia analitica para determinacao de mercurio total em amostras de urina por espectrometria de absorcao atomica com geracao de vapor frio (CV_AAS)." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9446.

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24

Bao, Yiping. "Investigation of the mechanisms by which UV irradiation activates the tyrosinase gene." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366716.

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25

Liang, Li Heng. "Statistical analysis and biological effects of prostate motion in ultrasound image-guided external beam radiotherapy." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81359.

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Biological effects and prostate motion were studied for prostate cancer patients treated with external beam radiotherapy. The prostate motion was determined using an ultrasound-based patient positioning system (BAT: B-mode Acquisition and Targeting) just after conventional patient setup. The changes in planned biological effects due to prostate motion were calculated for the prostate target organ and for the rectum and bladder normal tissues using TCP (tumor control probability) and NTCP (normal tissue complication probability) calculations, respectively. The prostate TCP calculations were carried out for both prostate PTV and GTV structures, whereas the rectum and bladder wall structures were used for the NTCP calculations.

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26

Mahee, Durude. "Numerical Simulation and Graphical Illustration of Ionization by Charged Particles as a Tool toward Understanding Biological Effects of Ionizing Radiation." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535381068931831.

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27

Tierney, David Patrick. "The effects of radiolytically generated free radicals on aqueous amylase samples." Thesis, University of Salford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366002.

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28

AQUINO, SIMONE. "Efeitos da radiacao gama no crescimento de Aspergillus flavus produtor de aflatoxinas e no emprego da tecnica da Reacao em Cadeia da Polimerase (PCR) em amostras de graos de milho inoculadas artificialmente." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11253.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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29

Watkin, Richard David. "Interaction of UVA (320-380 nm) radiation with human skin cells." Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311173.

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30

Boas, Fabricio de Almeida Souza Vilas. "Avaliação do potencial radiossensibilizador de uma tiossemicarbazona derivada de N(4)-Metil-Toluil-2-acetilpiridina e seu complexo de cobre sobre linhagens celulares de tumores cerebrais." CNEN - Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, 2010. http://www.bdtd.cdtn.br//tde_busca/arquivo.php?codArquivo=161.

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Fundação de Amparo a Pesquisa do Estado de Minas Gerais
A radioterapia é uma das principais abordagens terapêuticas utilizadas no tratamento do câncer e é indicada, principalmente, em casos onde as lesões são inoperáveis. No entanto, uma de suas limitações advém dos próprios efeitos biológicos da radiação, além de outros fatores tais como a radiorresistência inerente a alguns tipos tumorais, tais como os cerebrais. Então, a aplicação concomitante de agentes antineoplásicos com radioterapia vem sendo praticada na clínica de modo a maximizar o efeito benéfico do último e ao mesmo tempo minimizar os efeitos colaterais da exposição à radiação ionizante. Dentro deste contexto geral é importante a pesquisa de novos compostos que possam ser selecionados como protótipos para o desenvolvimento de agentes que possuam os menores efeitos adversos possíveis. As tiossemicarbazonas são uma classe de compostos sintéticos que apresenta um amplo perfil farmacológico e já demonstraram atividade antitumoral. Também já foi relatado que a complexação destes compostos com cátions metálicos pode ser capaz de torná-los mais eficazes. O objetivo do presente trabalho foi avaliar o potencial radiossensibilizador de uma tiossemicarbazona derivada de N(4)-metil-toluil-2-acetilpiridina e seu complexo com cobre sobre linhagens celulares de glioblastoma multiforme, o qual de todos os tumores cerebrais é o que apresenta a maior agressividade e o maior índice de morbidade. Foi avaliada a sensibilidade de linhagens celulares de glioblastoma com diferentes status de p53 RT2 e U87 (p53 selvagem) e T98 (p53 mutante) à radiação gama de uma fonte de 60Co. Os resultados de citotoxicidade indicaram que as linhagens em questão apresentam uma radiossensibilidade similar, p53-independente. Os efeitos citotóxicos da tiossemicarbazona Lac e seu complexo CuLac foram avaliados e os resultados indicaram que ambas possuem excelente efeito citotóxico na ordem de 10-8 M em todas as linhagens avaliadas, portanto menores que drogas como a hidroxiuréia, cisplatina e etoposídeo (IC50 entre 10-4 e 10-6 M em média). O tratamento com as tiossemicarbazonas seguido de 6 Gy de radiação gama se mostrou mais eficiente que o tratamento com radiação isolada em todas as linhagens. A complexação com cobre não alterou de modo significativo o efeito antitumoral da tiossemicarbazona livre sobre as linhagens testadas. Análises de fotomicrografias ópticas indicaram que todos os tratamentos ocasionaram alterações morfológicas, tais como arredondamento celular, redução do volume citoplasmático e surgimento de vesículas na membrana citoplasmática. O conjunto de dados indicam que a tiossemicarbazona Lac e seu complexo de cobre possuem potente efeito antitumoral e também induzem radiossensibilização nas linhagens testadas.
Radiation therapy is one of the main therapeutical approaches used for the treatment of cancer and is indicated, mostly, in cases which the lesions are inoperable. However, one of its limitations comes from its own biological effects, besides other factors such as the radioresistance inherent to some types of tumors like the cerebral ones. Therefore, the concurrent aplication of antineoplasic agentes with the radiation therapy has been used in the clinical pratice with the objective of maximize the benefical effects of the latter and at the same time minimize the side effects of the exposure to ionizing radiation. In this general context is important the research for new compounds that can be selected as prototypes for the development of agents that possess the least adverse effects as possible. The thiosemicarbazones are a class of synthetic compounds that present a broad pharmacological profile and have demonstrated antitumoral activity. Also has been reported that the coordination of these compounds to metallic cations may be capable of make them more effective. The objective of the present work was to evaluate the radiosensitizing potential of a thisemicarbazone derived from N(4)-methyl-tolyl-2-acetylpyridine and its copper complex against glioblastoma multiforme cell lines, which of all brain tumors types, are the most agressive and have the highest morbidity. The sensitivity of glioblastoma cell lines with different p53 status RT2 and U87 (p53 wild type) and T98 (p53 mutant) to gamma radiation from a 60Co source was assessed. Citotoxicity results indicated that the cell lines in study presented a similar radiosensitivity, p53-independent. The citotoxic effects of the thiosemicarbazone Lac and its complex CuLac were assayed and the results indicated that both possess na excelent effect at the order of 10-8 M in all cell lines evaluated, therefore smaller than drugs such as hydroxyurea, cisplatin and etoposide (IC50 between 10-4 and 10-6 M). The treatment with the thiosemicarbazones followed by a 6 Gy gamma radiation dose showed to be more effective than the radiation alone in all cell lines. Coordination to Cooper had not changed significantly the antitumoral effect of the free thiosemicarbazone agains the cell lines tested. Morphological analysis of optical photomicrographies indicated that all treatment caused alterations, such as cell rounding, diminishing of the cytoplasmic volume and rising of vesicles at the cytoplasmic membrane. Together these data indicate that the thiosemicarbazone Lac and its metallic complex possess potent antitimoral effect amd also induce radiosensitivity in the tested cell lines.

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31

SILVA, MURILO C. da. "Estudo das interacoes dos produtos de radiolise da agua com a miotoxina do veneno de Crotalus durissus terrificus." reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11763.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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32

QUEIROZ, ALVARO A. A. de. "Obtencao de copolimeros de enxerto via radiacao ionizante caracterizacao e estudo de suas propriedades hemocompativeis." reponame:Repositório Institucional do IPEN, 1993. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10347.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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33

AZEVEDO, LUCIANE H. "Avaliacao dos efeitos do laser em baixa intensidade na regiao da glandula tireoide de camundongos." reponame:Repositório Institucional do IPEN, 2002. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11063.

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34

POTENZA, MARCOS R. "Emprego da radiacao gama como tratamento quarentenario, visando o controle da traca OPOGONA SACCHARI (Bojer, 1856) ( lepidoptera: tineidae ) em banana ( Musa sp ) e dracena ( Dracaena fragans)." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10777.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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35

Schettino, Giuseppe. "Development of a focused X-ray source as a microprobe of cellular radiation response." Thesis, King's College London (University of London), 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311928.

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36

Playle, Laura Charlotte. "Radiation-induced apoptosis and cell cycle checkpoints in human colorectal tumour cell lines." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341501.

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ANDRADE, MAIRA F. de. "Comparação dos efeitos da terapia laser de baixa intensidade (lambda=660 nm ou lambda=780 nm) no tratamento de mucosite oral induzida por radiação ionizante em ratos." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11800.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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38

VILLAVICENCIO, ANNA L. C. H. "Avaliacao do efeito da radiacao de Co-60 na sobrevida de diferentes linhagens de camundongos .Radiomodificadores e resposta celular." reponame:Repositório Institucional do IPEN, 1988. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9906.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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39

Autsavapromporn, Narongchai. "The role of intercellular communication and oxidative metabolism in the propagation of ionizing radiation-induced biological effects." Thèse, Université de Sherbrooke, 2011. http://hdl.handle.net/11143/5814.

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Coordinated interactions of specific molecular and biochemical processes are likely involved in the cellular responses to stresses induced by different ionizing radiations with distinctive linear energy transfer (LET) properties. Here, we investigated the roles and mechanisms of gap junction intercellular communication and oxidative metabolism in modulating cell killing and repair of potentially lethal damage (PLDR) in confluent AG1522 human fibroblasts exposed to 1 GeV protons (LET~0.2 keV/[mu]m), [superscript 137]Cs [gamma] rays (LET~0.9 keV/[mu]m), [superscript 241]Am [alpha] particles (LET~122 keV/[mu]m) or 1 GeV/u iron ions (LET~151 keV/[mu]m) at doses by which all cells in the exposed cultures are irradiated. As expected, [alpha]-particles and iron ions were more effective than protons and [gamma] rays at inducing cell killing. Holding [gamma]- or proton-irradiated cells in the confluent state for several hours after irradiation promoted increased survival and decreased chromosomal damage. However, maintaining [alpha]-particle or iron ion-irradiated cells in the confluent state for various times prior to subculture resulted in increased rather than decreased lethality, and was associated with persistent DNA damage and increased protein oxidation and lipid peroxidation. Inhibiting gap junction communication with 18-[alpha]-glycyrrhetinic acid or by knockdown of connexin43, a constitutive protein of junctional channels in these cells, protected against the toxic effects expressed in these cells during confluent holding. Up-regulation of antioxidant defense by ectopic over-expression of glutathione peroxidase, protected against cell killing by [alpha]-particles when cells were analyzed shortly after exposure. However, it did not attenuate the decrease in survival during confluent holding. Together, these findings indicate that the damaging effect of [alpha] particles results in oxidative stress, and the toxic effects in the hours following irradiation are amplified by intercellular communication, but the communicated molecule(s) is unlikely to be a substrate of glutathione peroxidase. To further understand the role of GJIC, we tested the effect of specific connexin channel permeabilities on radiation-induced cell killing and induction of DNA damage. We used human adenocarcinoma (HeLa) cells in which specific connexins can be expressed in the absence of endogenous connexins. When exposed to protons, [gamma] rays, [alpha] particles, or iron ions, connexin26 and connexin43 channels mediated the propagation of toxic effects among irradiated cells; in contrast, connexin32 channels conferred protective effects. Collectively, these studies provide a novel mechanistic understanding of the molecular events that mediate the fate of cell populations exposed to different types of ionizing radiation. They show that the LET of the radiation significantly impacts these events. The enhancement of cell killing in the hours after exposure of tumor cells to high charge and high energy particles and or [alpha] particles support the use of these particles in cancer radiotherapy. Characterization of the molecules that are communicated through junctional channels from tumor to normal cells would help formulate countermeasures to protect normal tissues during radiotherapy. Future in vivo research would contribute to validating these concepts.

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40

Thiagarajah, Jay Ram. "Structure and function relationships in the colon : the role of the pericryptal sheath." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368218.

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MORENO, CAROLINA dos S. "Estudo do efeito radioprotetor do resveratrol." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9440.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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42

AMANCIO, FRANCISCO F. "Acao da radiacao ionizante sobre hemacias humanas e suas proteinas de membrana." reponame:Repositório Institucional do IPEN, 1998. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10690.

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IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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43

Kosmiskas, Luis Otavio Carvalho. "Análise mecânica de réguas ósseas esterilizadas por radiação gama para uso em bancos de tecidos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-30032012-111103/.

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Ao se trabalhar com materiais para a área de saúde, uma das principais considerações é evitar possíveis contaminações, dada a natureza da sua aplicação. Dentre os métodos desenvolvidos para esterilização, a radiação ionizante tem sido amplamente empregada por inúmeros setores da área de saúde pela sua eficácia em eliminar contaminantes biológicos de diversas origens. A problemática da utilização da radiação ionizante em materiais de origem humana, contudo, vai além da questão de sua eficácia como esterilizante, incluindo as possíveis alterações na estrutura do material de escolha. Desta forma, no presente trabalho, buscou-se avaliar qual a extensão das alterações biomecânicas causadas pela radiação em tecidos ósseos. Mais especificamente avaliamos as alterações no módulo de elasticidade, tensão de ruptura e porcentagem de deformação que decorrem do processo de irradiação. Como modelo de eleição foram escolhidas réguas ósseas retiradas da diáfase de fêmures bovinos, simulando as condições de ossos humanos armazenados em Bancos de Tecidos Biológicos. Estas foram congeladas a -70ºC e expostas a doses crescentes de radiação gama (0, 12.5, 25 e 50 kGy). Durante o trabalho foi desenvolvido um sistema de cortes para obtenção de amostras precisas e homogêneas. Os resultados demonstram que há uma diferença significativa entre as características observadas com o aumento da dose de radiação.
In the production process of health care products, contamination must be considered as one of the principal hazards to be avoided. Among the developed methods for sterilization, ionizing radiation has largely been used by many sectors in health care area as it is efficient in eliminating biological contaminants of several origins. The difficulty of deploying ionizing radiation in materials of human origin, though, includes which possible alterations it might cause in human tissue. In the present work, the extension of the biomechanical alteration generated by radiation in bone tissue was evaluated by biomechanical methods. More specifically, we evaluated alterations to the elastic modulus, rupture tension and percentage of deformation that are thought to be a consequence of the sterilization process. As a research model, bovine femur struts obtained from the diaphysis were used. The struts were frozen in a temperature of -70 ºC and irradiated with crescent doses of gamma radiation (0, 12.5, 25 e 50 kGy). During this work, a cutting system to obtain precision samples to use in such essays was developed. As results show that there is a significant different between the analyzed characteristics in the different doses of radiation.

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44

Ghajar, Feridon Ghasem Khan, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "Stimulatory and inhibitory effects of UVA and UVB radiation on some physiological and pathogenic characteristics of fungal biocontrol agents to enhance mycoherbistat effectiveness." THESIS_CSTE_SFH_Ghajar_F.xml, 2004. http://handle.uws.edu.au:8081/1959.7/621.

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Many candidate mycoherbicides have shown promise in the laboratory or greenhouse, but most have been ineffective in the field. Factors limiting mycoherbicide efficiency include temperature and humidity. Results from this thesis indicate that solar radiation has both a damaging effect(reduction in germination)limiting efficacy and a photomorphogenic effect(appressorium induction)increasing efficacy. The study has also shown significant interaction between temperature and solar radiation on the survival of conidia of potential mycoherbistats. Therefore, solar radiation should be considered as third major component of the environment that should be considered when trying to produce mycoherbistats. With the findings presented in this thesis and further research on disease development under different conditions, in combination with the formulation of conidia in suitable UV protectants, a computer simulation modelling the conditions leading to epidemics caused by C.orbiculare, D.avenacea and R.alismatis could be constructed. It may be possible to manipulate fungal application time in order to expose conidia to doses of solar radiation that are not harmful to conidium germination and which stimulate appressorium formation. However, additional protection may be needed.
Doctor of Philosophy (PhD)

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45

TALLARICO, LENITA de F. "Efeito letal dominante da radiacao gama de sup(60)Co em Biomphalaria glabrata (Say, 1818)." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11119.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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46

Kosanlavit, R. "The early effects of radiation on in vitro explants of mouse pancreas : a morphological and immunocytochemical study." Thesis, Queen's University Belfast, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368753.

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CARDI, BRUNO A. "Avaliacao do mecanismo de captacao e endocitose de crotoxina submetida a acao da radiacao gama, por macrofagos peritoneais de comundongos." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10749.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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48

MITAKE, MALVINA B. "Estudos bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gamma de sup(60)Co." reponame:Repositório Institucional do IPEN, 2000. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10819.

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Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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49

MURAKAMI, DANIELLA. "Efeitos das radiacoes gama (sup 60 Co) e beta (sup 90 Sr) em celulas de ovario de hamster chines (CHO-K1): inducao de micronucleos e morte celular." reponame:Repositório Institucional do IPEN, 2003. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11113.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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50

TALLARICO, LENITA de F. "Avaliacao dos efeitos toxicos e mutagenicos de amostras ambientais do Rio Tiete na regiao de Suzano em Biomphalaria glabrata (SAY, 1818)." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9382.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Dissertations / Theses on the topic 'Radiation Biological Effects'

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