Chan Yu-leung. / "Nov 2003." / Thesis (M.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 179-193). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

Cheung Mei-chun. / "January 2003." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (p. 66-94). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Assaying internal contamination due to inhalation is a primary concern in developing emergency procedures related to Radioactive Dispersal Devices (RDD). One method of determining internal contamination makes use of a common medical instrument, a Thyroid Uptake System (TUS). The TUS used in this research has two collimators a thyroid uptake collimator and a bioassay collimator. Both collimators were considered and modeled in MCNP to be used in conjunction with six MIRD-type (Medical Internal Radiation Dose) phantoms. The collimators were placed in four positions on the phantoms the front right lung, the back right lung, the neck, and the thigh. Unit sources of Cs-137, Co-60, I-131, Ir-192, Am-241, and Sr/Y-90 were placed in the organs of the phantoms. MCNP particle tallies were performed over the detector crystal volume to determine the count-rate contributions from the unit source in each organ. Biokinetic modeling was performed using DCAL (Dose and Risk Calculation System) to generate coefficients to describe activity as a function of time in various organs. By folding the count-rate results with the organ concentrations, the detector response as a function of time after intake has been determined. This work was performed under funding provided by the Radiation Studies Branch of the Centers for Disease Control and Prevention.

The purpose of this thesis is to present data pertinent to and propose conclusions regarding the coordination of radiobiologic effectiveness (RBE) and linear energy transfer (LET). RBE is a quantity relating the effectiveness of different radiations in causing cell death. LET is a measure of the rate of energy transferred to material by an ionizing particle. This relationship of these values varies for different particles. The reason for this is still inconclusive. The petitioner has made use of a toolkit for Geant4, known as Geant4-DNA, to perform track-structure analysis on a chromosome model. Geant4 is an object-oriented program for the "simulation of the passage of particles through matter" developed by CERN that makes use of Monte Carlo methods and is expanded by Geant4-DNA to handle low-energy electron physics as well as physic-chemical effects. The chromosome model, in this case, has been developed by the petitioner as a nucleus with a basic, uniform distribution of chromatin. Radiation damage to DNA, in the form of aberrations, lesions and strand breaks, can be coordinated to energy deposited or number of ionizations occurring in the target (in this case DNA or chromatin fiber). Certain threshold values have been established as indicate of different types of DNA damage. The ultimate goal of this work is to score these clusters of events against the threshold values to determine the severity of DNA damage. The final comparison of the results for different particles will provide for a better understanding of the RBE-LET relationships by improving the understanding of the underlying nanodosimetric qualities.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 6 uppsatser.

Thesis (Ph.D.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Department of Chemistry. Title from pdf file main screen (viewed on April 10, 2010). Includes bibliographical references.

Submitted by Maria Anália Conceição (marianaliaconceicao@gmail.com) on 2016-06-28T13:08:11Z No. of bitstreams: 1 Publico-NOVO-24.pdf: 1515165 bytes, checksum: 3b9206d6518639a99202f8ee9c5f29ad (MD5) / Approved for entry into archive by Maria Anália Conceição (marianaliaconceicao@gmail.com) on 2016-06-28T13:15:12Z (GMT) No. of bitstreams: 1 Publico-NOVO-24.pdf: 1515165 bytes, checksum: 3b9206d6518639a99202f8ee9c5f29ad (MD5) / Made available in DSpace on 2016-06-28T13:15:12Z (GMT). No. of bitstreams: 1 Publico-NOVO-24.pdf: 1515165 bytes, checksum: 3b9206d6518639a99202f8ee9c5f29ad (MD5) Previous issue date: 2015 / Introdução: A tolerância cutânea à radiação é o principal fator limitante da radioterapia. A escassez de estudos experimentais é imensa, principalmente em animais de médio porte, como os coelhos. Objetivo: Descrever um modelo experimental de radiodermatite em coelhos Métodos: Neste estudo foram utilizados 24 coelhos da raça Nova Zelândia, machos, com 6 meses de idade, peso médio de 2,5 Kg. Os mesmos foram distribuídos em 4 grupos (n=6 para cada grupo), sendo um grupo controle (sem nenhuma intervenção) e os demais submetidos à radioterapia com sessão única de 10, 20 e 30 Gy, respectivamente. Foram realizadas análises fotográficas e histopatológicas das áreas irradiadas. Resultados: Os animais do grupo controle após 30 dias da epilação apresentaram crescimento dos fâneros regularmente. Os animais do grupo 20 Gy e 30 Gy apresentaram alopecia com duração de 60 dias e 90 dias, respectivamente. A partir do dia 30, a área irradiada dos animais do grupo 30 Gy apresentou grau 3 e 4 de radiodermatite, persistindo por 90 dias. A redução progressiva da contagem de anexos, vasos sanguíneos e um aumento da deposição de colágeno foi significante, quando comparado o o grupo controle com o grupo de 30 Gy. Conclusão: A dosagem de 30 Gy é a mais eficaz para este modelo experimental de radiodermatite. / Introduction: The cutaneous tolerance is a limiting factor for this oncologic treatment. The lack of experimental models is enormous, primarily for mid size animals, such as rabbits. Purpose: Describe an experimental model of cutaneous radiation injury in rabbits Methods: On this study 24 six-month-old New Zealand male rabbits, with an average weight of 2.5kg, were used. They were distributed in 4 groups (n=6 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 10, 20 and 30Gy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. Results: After 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 20Gy had a 60-day alopecia and from group 30Gy, a 90-day alopecia. After the 30th day, the 30Gy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was significant, when the control group is compared to the group 30Gy. Conclusion: This study demonstrates the dosage 30Gy is the most effective for this experimental model of cutaneous radiation injury in rabbits.

Made available in DSpace on 2014-10-09T12:30:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:26Z (GMT). No. of bitstreams: 1 12910.pdf: 3374698 bytes, checksum: 5941c584a71790c96853ebeca9e2c146 (MD5) / Tese (Doutoramento) / IEA/T / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP

Made available in DSpace on 2014-10-09T12:30:06Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:26Z (GMT). No. of bitstreams: 1 12910.pdf: 3374698 bytes, checksum: 5941c584a71790c96853ebeca9e2c146 (MD5) / Tese (Doutoramento) / IEA/T / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP