• Journal of Radiation Industry
• /
• v.7 no.1
• /
• pp.55-59
• /
• 2013

Ionizing radiation causes the massive generation of reactive oxygen species, resulting in cellular and tissue damage. The present study was performed to evaluate ${\gamma}$-irradiation induced cellular damage in ICR mice. The mice were divided into four groups with ten mice in each group. Group 1 served as an unexposed control group. Groups 2, 3, and 4 were exposed to 3, 5, and 7 Gy of ${\gamma}$-radiation, respectively. Five mice per group were sacrificed 1 and 7 days after ${\gamma}$-radiation. Exposure to ${\gamma}$-irradiation resulted in hematopoietic damage in a dose-dependent manner when compared with the unexposed control group, which featured a significantly decreased spleen index. However, the exposed mice showed no significant differences in their serum AST, ALT and in the histopathological change of their liver. These results suggest that ${\gamma}$-irradiation is a good tool to prepare a hematopoietic damage model. This animal model can be employed to study the hematopoietic efficacy of biologically active compounds.

• The Journal of Korean Society for Radiation Therapy
• /
• v.23 no.2
• /
• pp.97-102
• /
• 2011

Purpose: IMRT QA using 2Dimensional array detector is carried out with condition for discrete dose distribution clinically. And it can affect uncertainty of evaluation using gamma method. We analyze gamma index variation according to grid size and suggest validate range of grid size for IMRT QA in Hospital. Materials and Methods: We performed QA using OniPro I'mRT system software version 1.7b on 10 patients (head and neck) for IMRT. The reference dose plane (grid size, 0.1 cm; location, [0, 0, 0]) from RTP was compared with the dose plane that has different grid size (0.1 cm, 0.5 cm, 1.0 cm, 2.0 cm, 4.0 cm) and different location (along Y-axis 0 cm, 0.2 cm, 0.5 cm, 1.0 cm). The gamma index variation was evaluated by observing the level of changes in Gamma pass rate, Average signal, Standard deviation for each case. Results: The average signal for each grid size showed difference levels of 0%, -0.19%, -0.04%, -0.46%, -8.32% and the standard deviation for each grid size showed difference levels of 0%, -0.30%, 1.24%, -0.70%, -7.99%. The gamma pass rate for each grid size showed difference levels of 0%, 0.27%, -1.43%, 5.32%, 5.60%. The gamma evaluation results according to distance in grid size range of 0.1 cm to 1.0 cm showed good agreement with reference condition (grid size 0.1 cm) within 1.5% and over 5% in case of the grid size was greater than 2.0 cm. Conclusion: We recognize that the grid size of gamma evaluation can make errors of IMRT QA. So we have to consider uncertainty of gamma evaluation according to the grid size and apply smaller than 2 cm grid size to reduce error and increase accuracy clinically.

• Journal of Nutrition and Health
• /
• v.35 no.3
• /
• pp.368-379
• /
• 2002

This study investigated the correlations among the health consciousness, nutrition knowledge, dietary habits and nutrition attitudes of school teachers. The subjects of this study were 75 male and 152 female leachers in elementary and middle schools in Masan city. The survey was conducted by using a questionnaire. Even though the average body mass index (BMI) and the obesity index were normal in both male and female subjects, 33.3% of the male subjects were overweight/obese, while 18.5% of the female subjects were underweight, according to the obesity index. The food components of most concern during mealtime were (in order of importance) salt, MSG and cholesterol by male subjects, and salt, fat and MSG by female subjects. The subjects considered self-relaxation as the most important factor in maintaining optimal health status, followed by resting, bathing or use ova sauna, moderation in diet, exercise, decreasing alcohol intake, and no smoking. Newspapers/magazines and TV/radio were the primary sources of nutrition and health information of the subjects. As the degree of health consciousness increased, scores of the dietary habits and nutrition attitudes increased. Nutrition knowledge scores and nutrition altitudes scores increased with subjects'increased level of perception of the importance of acquiring nutrition knowledge and nutrition information. There was a highly significant correlation between the degree of health consciousness and dietary habit score (${\gamma}$ : 0.3, p<0.001). The degree of health consciousness was also significantly correlated (${\gamma}$=0.6, p<0.001) with nutrition attitudes scores. But the correlation between the degree of health consciousness and nutrition knowledge was not statistically significant. The degree of the perception of the importance of nutrition knowledge showed a positive correlation with nutrition attitude (${\gamma}$:0.4, p<0.001) and dietary habit (${\gamma}$:0.3, p<0.001). The degree of perception about the importance of nutrition knowledge and nutrition information was positively correlated with nutrition knowledge (${\gamma}$:0.2, p<0.001) and nutrition attitudes (${\gamma}$:0.3, p<0.001).

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.95.2-95.2
• /
• 2012

We have compared the geoeffective parameters of halo coronal mass ejections (CMEs) to predict geomagnetic storms. For this we consider 50 front-side full halo CMEs whose asymmetric cone model parameters and earthward direction parameter were available. For each CME we use its projected velocity (Vp), radial velocity (Vr), angle between cone axis and sky plane (${\gamma}$) from the cone model, earthward direction parameter (D), source longitude (L), and magnetic field orientation (M) of the CME source region. We make a simple and multiple linear regression analysis to find out the relationship between CME parameters and Dst index. Major results are as follows. (1) $Vr{\times}{\gamma}$ has a higher correlation coefficient (cc = 0.70) with the Dst index than the others. When we make a multiple regression of Dst and two parameters ($Vr{\times}{\gamma}$, D), the correlation coefficient increases from 0.70 to 0.77. (2) Correlation coefficients between Dst index and $Vr{\times}{\gamma}$ have different values depending on M and L. (3) Super geomagnetic storms (Dst ${\leq}$ -200 nT) only appear in the western and southward events. Our results demonstrate that not only the cone model parameters together with the earthward direction parameter improve the relationship between CME parameters and Dst index but also the source longitude and its magnetic field orientation play a significant role in predicting geomagnetic storms.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.2
• /
• pp.115-122
• /
• 2015

Purpose : The aim of this study, evaluate the accuracy of HeaxPOD evo RT system using the non-coplanar beam. Materials and Methods : 13 treatment plans are used which applied non-coplanar beams and 10 treatment plans which coplanar beams are used. the correction value what adjust to 6D couch is determined by each patient's setup errors only rotation direction. The study executed followings. first, Applying the correction value, measure the point dose and calculate the ${\gamma}$-index(${\gamma}=3%$ / 3 mm, ${\gamma}=2%$ / 2 mm). second, acquire data as previous methods without correction by HexaPOD. Results : For comparing the two results, we find out the more precise applying HexaPOD by point dose 0.2% in coplanar and non-coplanar. in the case of ${\gamma}$-index<1(${\gamma}=3%$ / 3 mm), more precise 2.2% in coplanar and 7% in Non-coplanar. Particularly, ${\gamma}$-index<1(2% / 2 mm) show the difference 9.2% in coplanar and 15.1% non-coplanar between apply HexaPOD and dose not apply HexaPOD. Conclusion : Using the HexaPOD is more precise than without HexaPOD. It suggests that HexaPOD evo RT system is very useful for precise and high dose delivery.

• Journal of Acupuncture Research
• /
• v.25 no.6
• /
• pp.47-54
• /
• 2008

Objectives : This study was aimed to figure out how effectively acupuncture treatment and herb-medicine work on patients with elevation of LFT value and lipid-obesity index. Methods : The subject were 23 patients visited to Dept. of Acupuncture and Moxibustion, Kwangdong Oriental Medicine Hospital, who complained chronic fatigue and wandering pain from Oct. 2007. to Oct. 2008. Before treatments, they were tested for LFT, total cholesterol, triglyceride, body fat ratio and obesity index. They were treated with Ganjeonggyeok acupuncture weekly for 1 month. During acupuncture treatments, we applied Sangkankunbi-tang to all patients twice a day. After 1 month, they were retested for LFT, total cholesterol, triglyceride, body fat ratio and obesity index. Results : 1. After treatments, we could get the result of dropping means of AST, ALT and $\gamma$-GTP value. Statistical significance of ALT and $\gamma$-GTP were recognized before and after treatments, but AST was not recognized. 2. After treatments, we also could get the result of dropping means of total cholesterol, triglyceride, body fat ratio and obesity index. Statistical significance of all values were recognized before and after treatments. 3. Among 23 patients, 10 cases were reported that they were not within normal limits at least one in AST, ALT and $\gamma$-GTP. After treatments of those patients, we could get the result of dropping means of AST, ALT and $\gamma$-GTP value. Statistical significance of all values were recognized before and after treatments. 4. Among 23 patients, 19 cases were reported that they were not within normal limits at least one in total cholesterol, triglyceride, body fat ratio and obesity index. After treatments of those patients, we could get the result of dropping means of total cholesterol, triglyceride, body fat ratio and obesity index. Statistical significance of all values were recognized before and after treatments. Conclusions : Though further study is necessary, our finding suggest that the conduction of Ganjeonggyeok acupuncture and Sangkankunbi-tang treatments have helped to decrease the figures of LFT and lipid-obesity index in patients.

• Preventive Nutrition and Food Science
• /
• v.13 no.4
• /
• pp.354-361
• /
• 2008

A novel bacterium isolated from Cheonggukjang was identified as a glutamate-dependent Bacillus subtilis HA with 98.3% similarity to Bacillus subtilis Z99104. Optimization of poly-$\gamma$-glutamic acid ($\gamma$-PGA) production by modulating fermentation factors including carbon sources, nitrogen sources, inorganic salts and fermentation time was investigated. Optimum culture broth for $\gamma$-PGA production consisted of 3% glutamate, 3% glucose and various salts, resulting in the PGA production of 22.5 g/L by shaking culture for 72 hr at $37^{\circ}C$. Average molecular weight of $\gamma$-PGA was determined to be 1,220 kDa through MALLS analysis. The $\gamma$-PGA solution showed a typical pseudoplastic flow behavior, and a great decrease in consistency below pH 6.0 regardless of the same molecular weight of $\gamma$-PGA. The molecular weights of isolated $\gamma$-PGA were drastically decreased by heat treatment in various acidic conditions, resulting in different hydrolysis of $\gamma$-PGA. The consistency of $\gamma$-PGA solution was greatly decreased with increase heating time in acidic conditions.

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.49.3-50
• /
• 2015

Synchrotron radiation of relativistic electrons is an important radiation mechanism in many astrophysical sources. In the sources where the synchrotron cooling timescale is shorter than the dynamical timescale, electrons are cooled down below the minimum injection energy. It has been believed that such fast-cooling electrons have a power-law distribution in energy with an index -2, and their synchrotron radiation has a photon spectral index -1.5. On the other hand, in a transient expanding astrophysical source, such as a gamma-ray burst (GRB), the magnetic field strength in the emission region continuously decreases with radius. Here we study such a system, and find that in a certain parameter regime, the fast-cooling electrons can have a harder energy spectrum. We apply this new physical regime to GRBs, and suggest that the GRB prompt emission spectra whose low-energy photon spectral index has a typical value -1 could be due to synchrotron radiation in this moderately fast-cooling regime.

• The Korean Journal of Applied Statistics
• /
• v.27 no.1
• /
• pp.103-114
• /
• 2014

Significant research has been devoted to the consistency index of the Analytic Hierarchy Process(AHP) from several perspectives. Critics of the consistency index in AHP state that the critical value of consistency index depends on an average of the random index based simulation study using a 9 scale comparison matrix. We found that the distribution of the consistency index followed the skew distribution according to the dimension of the comparison matrix based on a simulation study with a 9 scale comparison matrix. From the simulation study, we suggest a consistency index quantile table to assist the decision-making process in AHP; in addition, we can approximate the distribution of the consistency index to the gamma distribution under the limited assumptions.

• Polymer(Korea)
• /
• v.30 no.1
• /
• pp.10-13
• /
• 2006

The effects of antioxidants and thermal treatment on the radiation resistance of the gamma-ray irradiated polypropylene (PP) were studied. The PP was blended with various antioxidants and was fabricated into a sheet. The PP sheet was irradiated with gamma-ray to a dosage of 25kGy in the nitrogen atmosphere. The differences in both color and mechanical strength were investigated for the gamma-ray irradiated PP depending on the kind and the content of antioxidant. The residual amount of free radical and the variation of oxidation index were investigated for the gramma-ray irradiated PP with thermal treatment after irradiation. The PP having phosphite antioxidant showed little difference in color after gamma-ray irradiation compared with the PP having phenolic or mine antioxidant. Sufficient amount of free radical could be removed from the gamma-ray irradiated PP by the thermal treatment at $130\;^{\circ}C$ for 30 min. Thermally treated PP showed lower oxidation index than the PP without thermal treatment.