• Journal of the Korean Society of Radiology
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• 제10권8호
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• pp.591-596
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• 2016

The purpose of this study is to determine the equivalent energy of a 6MV X-ray beam in the experiment. The half-value layer (HVL) of lead for the 6 MV X-ray beam was measured using an ionization chamber. The linear attenuation coefficients were calculated with HVL. And, the mass attenuation coefficient was obtained by dividing the linear attenuation coefficient by the density of lead. The equivalent energy of mass attenuation coefficient was determined using the photon energy versus mass attenuation coefficient data of lead given by National Institute of Standards and Technology (NIST). In conclusion, the equivalent energy of the 6 MV X-ray beam was determined to be 1.61 MeV. This equivalent energy was determined to be about 30% lower than reported by Reft. The reason is presumed to be due to the presence of an air cavity between the lead attenuators.

• Molecules and Cells
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• 제39권12호
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• pp.877-887
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• 2016

Tazarotene-induced gene 1 (TIG1) is a retinoic acid-inducible protein that is considered a putative tumor suppressor. The expression of TIG1 is decreased in malignant prostate carcinoma or poorly differentiated colorectal adenocarcinoma, but TIG1 is present in benign or well-differentiated tumors. Ectopic TIG1 expression led to suppression of growth in cancer cells. However, the function of TIG1 in cell differentiation is still unknown. Using a yeast two-hybrid system, we found that transmembrane protein 192 (TMEM192) interacted with TIG1. We also found that both TIG1A and TIG1B isoforms interacted and co-localized with TMEM192 in HtTA cervical cancer cells. The expression of TIG1 induced the expression of autophagy-related proteins, including Beclin-1 and LC-3B. The silencing of TMEM192 reduced the TIG1-mediated upregulation of autophagic activity. Furthermore, silencing of either TIG1 or TMEM192 led to alleviation of the upregulation of autophagy induced by all-trans retinoic acid. Our results demonstrate that the expression of TIG1 leads to cell autophagy through TMEM192. Our study also suggests that TIG1 and TMEM192 play an important role in the all-trans retinoic acid-mediated upregulation of autophagic activity.

• Journal of the Korean Society of Radiology
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• 제9권3호
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• pp.125-130
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• 2015

RI & RG are used in various field such as medical field, industrial field, agricultural and food&life field. The number of small nuclear facilities is on the increase. We need to take an interest in decommissioning of small nuclear facility and predict the occurring problem from facility decommissioning. Because of the relatively low radiation risk, the preparation of the small nuclear facility dismantling is often neglected. As the accident in Goiania, Brazil showed, the impact of the decommissioning of small nuclear facilities is not less than the large nuclear facilities although it may seem dangerless. Therefore, we analyzed the each institutional characteristics of the decommissioning of small nuclear facilities through foreign case study on this research. Also, we proposed several considerations on decommissioning such as reuse of facility and source, lack of space, stakeholder involvement and failures of protection. Through these study, we tried to make guideline of the small nuclear facilities decommissioning.

• Korean Journal of Head & Neck Oncology
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• 제24권2호
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• pp.169-173
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• 2008

Purpose：This is a retrospective study to evaluate the results of concurrent chemoradiotherapy in nasopharyngeal carcinoma. Material and Methods：From Mar 2000 to June 2005, 18 patients with nasopharyngeal carcinoma completed planned concurrent chemoradiotherapy. Stages were I in 1 patients, II in 2 patients, III in 7 patients and IV in 8 patients. Pathologic type was squamous cell carcinoma(WHO type 1) in 2 patients, non-keratinizing type(WHO type 2) in 8 patients and undifferetiated carcinoma(WHO type 3) in 8 patients. The follow up period ranged from 30 months to 95 months with a median of 56 months. Follow up was possible in all patients. Results：Response to concurrent chemoradiation therapy was a complete response in all patients. Patterns of failure were as follows：local recurrence in only one patient(5.6%) and distant metastases in three patients with N3 diseases(16.7%). The overall 5 year survival rates were 88.5%, the 5 year disease free survival rate was 77% and these were very good results. There were no significant differences in the local control and survival rates between the clinical stages and pathologic types. Conclusion：The outcome of the nasopharyngeal carcinoma treated with concurrent chemoradiotherapy was very good, even though most of the patients(15/18=83.3%) were in stage III and IV diseases. We concluded that concurrrent chemoradiotherapy in nasopharyngeal carcinoma showed the good local control and survival rates without significant complications. In the patients with N3 disease, we have to consider the more effective and strong chemotherapeutic regimens to prevent distant metastases.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제41권2호
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• pp.89-93
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• 2008

Goldfish were exposed to radioactive isotope $^{18}F$, which is used for positron emission tomography (PET). $^{18}F$ is created when the oxygen in water combines with hydrogen on exposure to positrons accelerated by a cyclotron. The temporal change in intestine contractility was measured by physiograph after the exposure to $^{18}F$. The distance between the goldfish and 580 mCi of $^{18}F$ was approximately 4 cm and the exposure was for 4 hrs. The absorption level calculated from the distance, exposure time, and half-life of $^{18}F$ was approximately 2 Gy. The contractile activity of goldfish intestine was lowest on the first day and increased gradually to 100% of the control level by a period of between 5 and 36 days.

• The Korean Journal of Pain
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• 제30권2호
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• pp.126-133
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• 2017

Background: There are many mechanisms in which stress can lead to weight gain thus high a BMI. The endocrine and inflammatory pathway can directly increase abdominal adiposity. Another way in which stress leads to weight gain is through changes in health behaviors. The study aimed to investigate the prevalence of musculoskeletal disorders (MSDs) among healthy students of Ahlia University, and to determine the relationship between the development of MSDs and academic stressors and body mass index. Methods: Self-administered questionnaires were distributed to 94 students aged 18-26 years who were enrolled at various Ahlia University colleges and met other inclusion criteria. The students responded to the standardized Nordic musculoskeletal questionnaire and the modified College Student Stress Inventory regarding musculoskeletal symptoms and academic stressors. Height and weight measurements were also obtained to determine body mass index. Results: A total of 77.66% reported MSDs in one or more body part, with the prevalence being higher among women than among men. The 7-day prevalence of MSDs severe enough to interfere with activities of daily living was 60.64%, and 44.68% by female and male students, respectively. There was a significant relationship between academic stress and MSDs in the neck, shoulders, lower back, and hips, while the relationship between MSDs, and body mass index, academic stress, and grade point average was not significant. Conclusions: The prevalence of MSDs among Ahlia University students was found to be high. Apart from the positive correlation between academic stress and MSDs in certain body parts, other correlations were not significant.

• The Korea Journal of Herbology
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• 제20권3호
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• pp.19-27
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• 2005

Objectives : The antioxidant activities of Yeonkyo-san and its ingredient were investigated for industrial application. Methods : We experimented radical scavenging effect, superoxide dismutase and cytotoxicity effect of various cancer cell. Results : The result were obtained as follows : Primary testing of cytotoxicity of Yeonkyo-san and ingredient was done for G361. B16F10, MDA and A549 cell lines. Yeonkyo-san and ingredient water extract, ethanol extract showed cytotoxicity of over 90% respectively against cell line. The electron donating ability(EDA) of water extract from the Yeonkyo-san was higher than 60%, ethanol extract from the Yeonkyo-san was over 80% at 1000 ppm. The electron donating ability(EDA) of water extract and ethanol extract from the Yeonkyo-san ingredients were increased as well. SOD-like activity was high as 75% in 700 ppm, it was increased. All the other samples showed less than 40% SOD-like activity. Conclusions : The results indicated that water extract and ethanol extract of Yeonkyo-san and ingredient can be used as a natural ingredient with biological functions in cosmetic and food composition.

• Progress in Medical Physics
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• 제23권4호
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• pp.303-308
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• 2012

The Geant4 based Monte Carlo code for the application of stereotactic radiosurgery was developed. The probability density function and cumulative density function to determine the incident photon energy were calculated from pre-calculated energy spectrum for the linac by multiplying the weighting factors corresponding to the energy bins. The messenger class to transfer the various MLC fields generated by the planning system was used. The rotation matrix of rotateX and rotateY were used for simulating gantry and table rotation respectively. We construct accelerator world and phantom world in the main world coordinate to rotate accelerator and phantom world independently. We used dicomHandler class object to convert from the dicom binary file to the text file which contains the matrix number, pixel size, pixel's HU, bit size, padding value and high bits order. We reconstruct this class object to work fine. We also reconstruct the PrimaryGeneratorAction class to speed up the calculation time. because of the huge calculation time we discard search process of the ThitsMap and used direct access method from the first to the last element to produce the result files.

• Macromolecular Research
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• 제13권4호
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• pp.293-296
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• 2005

Transferrin ($T_{f}$) has been used as a targeting ligand for delivering liposome/interleukin-12 (IL-12) pDNA complexes to cancer cells mostly due to the greater number of transferrin receptors ($T_{f}R$) found on tumor cells than on normal cells. $T_{f}$ was conjugated to liposomes via the reaction of MPB-PE with thiol groups of $T_{f}$ introduced by a heterobifunctional cross-linking agent, N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP). Four days after C26 inoculation when the tumor volume reached ${\sim}100mm^{3}$, tumor-bearing Balb/c mice were injected intravenously with $T_{f}-liposome/IL-12 pDNA$complexes twice a week for 3 weeks. Significant suppression of tumor growth was achieved in the group treated with the $T_{f}-liposome/IL-12 pDNA$ complexes, with a dose of $10{\mu}g$ of IL-12 pDNA showing the highest suppression effect among the tested doses. Similar results were obtained when the therapy was initiated one day after tumor inoculation, although in this case $30{\mu}g$ IL-12 pDNA/$T_{f}-liposome$ complexes showed a significant suppression of tumor growth between 19 and 23 days after tumor inoculation. This result indicates that the transferrin receptor-targeted liposomal system is an efficient delivery agent of therapeutic genes, such as IL-12, in mice and that its potential clinical use warrants further research investigation.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2334-2338
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• 2020

In recent years, 3D printing technology has received significant research attention. Additionally, 3D printing technology is being applied to study radiation dosimeters of various materials. In this study, a plastic scintillator for 3D printing was developed in a laboratory and used to manufacture a plastic scintillation dosimeter (PSD) with a shape identical to that of the ionization chamber PTW31010. The 16-mm beam of Gamma Knife® Perfexion™ was irradiated to derive the absorbed dose rates of the PSD and PTW31010; they were subsequently compared with the dose rates of the treatment plan. The differences in the dose rates of the Gamma Knife treatment plan and the absorbed dose rates of PTW31010 were within 0.87%. The difference between the dose rates of the Gamma Knife treatment plan and the absorbed dose rates of the PSD were within 4.1%. A linear fit of the absorbed dose rates of four shots involving different dose rates and irradiation angles yielded an adjusted R-square value exceeding 0.9999. A total of 10 repeated measurements were conducted for the same shot to confirm its reproducibility, with a relative error of 0.56%.