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Kaviani, Ahmad,Neishaboury, MohamadReza,Mohammadzadeh, Narjes,Ansari-Damavandi, Maryam,Jamei, Khatereh Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4
Background: As data on the relation between obesity and lymph node ratio are missing in the literature, we here aimed to assess the impact of obesity on this parameter and other clinicopathological features of breast cancer cases and patient survival. Materials and Methods: Medical data of 646 patients, all referred to two centers in Tehran, Iran, were reviewed. Factors that showed significant association on univariate analysis were entered in a regression model. Kaplan-Meier and Cox-regression were employed for survival analysis. Results: Obesity was correlated with the expression of estrogen and progesterone receptor (p=0.004 and p=0.039, respectively), metastasis to axillary lymph nodes (p=0.017), higher lymph node rate (p<0.001) and larger tumor size (p<0.001). The effect of obesity was stronger in premenopausal women. There was no association between obesity and expression of human epidermal growth factor receptor. Three factors showed independent association with BMI on multivariate analysis; tumor size, estrogen receptor and lymph node ratio. Obesity was predictive of shorter disease-free survival with a hazard ratio of 3.324 (95%CI: 1.225-9.017) after controlling for the above-mentioned variables. Conclusions: The findings of this study support the idea that obese women experience more advanced disease with higher axillary lymph node ratio, and therefore higher stage at the time of diagnosis. Furthermore, obesity was associated with poorer survival independent of lymph node rate.
Dosimetric and Microdosimetric Characteristics of 9.6 to 30α-MeV Proton Beams
Mitra Ghergherehchi,채종서,Hossein Afarideh,Ahmad Mohammadzadeh 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.5
High and intermediate energy protons are not able to directly form a track in an etch detector (TED). Such detectors can, however, be used for the detection and dosimetry of beams of these particles through the registration of secondary charged particles with sufficiently high values of linear energy transfer (LET).Intermediate energy protons (10 to 30 MeV) with low LET values ranging from 5.87 down to 2.40 keV/탆 are considered. Although the LET values are low, this energy range seems to be sufficient to create secondary particles with much higher LET values through nuclear reactions in the irradiated matter. This phenomenon can modify the characteristics of the energy transfer process due to these particles, and it should be taken into account when such particles are used for radiobiology and/or radiotherapy studies. The importance of these secondary particles was studied experimentally by means of a LET spectrometer based on a chemically etched track detector, in which the tracks of the primary protons are not revealed. These studies were performed with protons whose primary energies were in the range of about 10 to 30 MeV, which are available at the Cyclotron Accelerator Department of Nuclear Research Center for Agriculture and Medicine (NRCAM) in Karaj, Iran. The microdosimetric distributions of the secondary particles mentioned above are presented, and their contributions to the absorbed dose of the primary protons are estimated. The contribution of the secondary particle dose increases with decreasing proton energy. The importance of this phenomenon in some applications is discussed. The origin of the secondary particles in interactions with protons having high and intermediate energies due to various nuclear reactions was calculated by using the Alice computer code. There is good agreement between the experimentally obtained and theoretically calculated results.