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1.
Iranian Journal of Cancer Prevention. 2014; 7 (1): 40-47
em Inglês | IMEMR | ID: emr-148707

RESUMO

Alpha particle irradiation from radon progeny is one of the major natural sources of effective dose in the public population. Oncogenic transformation is a biological effectiveness of radon progeny alpha particle hits. The biological effects which has caused by exposure to radon, were the main result of a complex series of physical, chemical, biological and physiological interactions. The cellular and molecular mechanisms for radon-induced carcinogenesis have not been clear yet. Various biological models, including cultured cells and animals, have been found useful for studying the carcinogenesis effects of radon progeny alpha particles. In this paper, sugars cape cellular automata have been presented for computational study of complex biological effect of radon progeny alpha particles in lung bronchial airways. The model has included mechanism of DNA damage, which has been induced alpha particles hits, and then formation of transformation in the lung cells. Biomarkers were an objective measure or evaluation of normal or abnormal biological processes. In the model, the metabolism rate of infected cell has been induced alpha particles traversals, as a biomarker, has been followed to reach oncogenic transformation. The model results have successfully validated in comparison with "in vitro oncogenic transformation data" for C3H 10T1/2 cells. This model has provided an opportunity to study the cellular and molecular changes, at the various stages in radiation carcinogenesis, involving human cells. It has become well known that simulation could be used to investigate complex biomedical systems, in situations where traditional methodologies were difficult or too costly to employ


Assuntos
Pulmão , Radônio , Partículas alfa
2.
Iranian Journal of Cancer Prevention. 2012; 5 (2): 61-68
em Inglês | IMEMR | ID: emr-178354

RESUMO

Mammography is the primary imaging technique for detection and diagnosis of breast cancer; however, the contrast of a mammogram image is often poor, especially for dense and glandular tissues. In these cases the radiologist may miss some diagnostically important microcalcifications. In order to improve diagnosis of cancer correctly, image enhancement technology is often used to enhance the image and help radiologists. This paper presents a comparative study in digital mammography image enhancement based on four different algorithms: wavelet-based enhancement [Asymmetric Daubechies of order 8], Contrast-Limited Adaptive Histogram Equalization [CLAHE], morphological operators and unsharp masking. These algorithms have been tested on 114 clinical digital mammography images. The comparison for all the proposed image enhancement techniques was carried out to find out the best technique in enhancement of the mammogram images to detect microcalcifications. For evaluation of performance of image enhancement algorithms, the Contrast Improvement Index [CII] and profile intensity surface area distribution curve quality assessment have been used after any enhancement. The results of this study have shown that the average of CII is about 2.61 for wavelet and for CLAHE, unsharp masking and morphology operation are about 2.047, 1.63 and 1.315 respectively. Experimental results strongly suggest that the wavelet transformation can be more effective and improve significantly overall detection of the Computer-Aided Diagnosis [CAD] system especially for dense breast. Compare to other studies, our method achieved a higher CII


Assuntos
Humanos , Feminino , Neoplasias da Mama/diagnóstico , Intensificação de Imagem Radiográfica , Calcinose , Análise de Ondaletas
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