• Journal of the Korea Academia-Industrial cooperation Society
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• 제17권8호
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• pp.442-448
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• 2016

This study was conducted to determine the appropriateness of systemic radiation exposure control for students in clinical practice by comparing radiation exposure in radiography employees at different stations of a hospital with that of students conducting clinical practice using identical stations. Overall, 121 students who conducted clinical practice in the department of radiology area of C university hospital from July 2014 to August 2014 and 62 workers working in the same medical facility (47 in the department of radiology, 8 in the department of radiation oncology, 7 in the department of nuclear medicine) were investigated. The radiation exposure experienced by students was measured for 8 weeks, which is the duration of the clinical practice. Additionally, radiation exposure of workers were classified into 4 groups, department of radiology, department of radiation oncology, and department of nuclear medicine was compared. Dose was measured with OSLD and differences among groups were identified by ANOVA followed by Duncan's multiple range test. Among employees, those in the department of radiology, oncology and nuclear medicine were exposed depth doses of $0.127{\pm}0.331mSv$, $0.01{\pm}0.003mSv$, and $0.431{\pm}0.205mSv$, respectively, while students were exposed to $0.143{\pm}0.136mSv$. Additionally, workers in the department of radiology, oncology and nuclear medicine were exposed to surface doses of $0.131{\pm}0.331mSv$, $0.009{\pm}0.003mSv$, and $0.445{\pm}0.198mSv$, respectively, while students were exposed to $0.151{\pm}0.14mSv$, which was significantly different in both doses (p < 0.01). The average dose that students received is higher than that of the other groups (except for nuclear medicine workers), indicating that further improvements must be made in systemic controls for individual radiation exposure by including the students as subjects of management for protection from radiation.

• Korean Journal of Agricultural Science
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• 제42권4호
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• pp.325-333
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• 2015

The ventilation systems composed three types of side vent (roll-up) 'SV', side vent+roof vent 'SV+RV', and side vent+roof fan 'SV+RF' with 7.5 m spacing, with specific set point temperatures for ventilation: SV ($35^{\circ}C$ open / $33^{\circ}C$ close), SV+RV or SV+RH ($35^{\circ}C$ open/$33^{\circ}C$ close for root ventilation and $37^{\circ}C$ open / $35^{\circ}C$ close for side vent). In the treatment of SV+RV, although the average daily maximum temperature inside the greenhouse temporarily increased by $38-40^{\circ}C$, thermal stress by high temperature did not occur and the disease incidence (%) of powdery mildew and downy mildew on the oriental melon were 25 - 75% lower than in the conventional SV treatment. In the SV treatment, the disease incidence (%) of powdery mildew and downy mildew were 1.4 - 7.7% and 4.2 - 15.9% for 'Deabakkul', and 20.3 - 22.8% and 2.8 - 11.3%, for 'Ildeungkkul'. The yield for one month was higher in the treatment of SV+RV than those in other treatments, with values of 2,105 kg/10a for 'Deabakkul' and 2,537 kg/10a for 'Ildeungkkul'. The simultaneous treatment with side vent and roof vent resulted in 16.2% higher yield (18.1% higher marketable yield) than that in the SV treatment for 'Deabakkul'.

• Journal of the Korean Society of Radiology
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• 제5권4호
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• pp.195-200
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• 2011

The purpose of this study is to investigate the dose of radiation exposure to radiation-related workers in a hospital setting, thus increasing awareness of the health risk to the radiation-related workers. The result of the analysis showed the average dose of radiation exposure to radiation-related workers in hospital K was $0.75{\pm}0.26mSv$ in 2008, $0.67{\pm}0.30mSv$ in 2009, and $0.92{\pm}0.33mSv$ in 2010. The average dose of radiation exposure in hospital P was $0.43{\pm}0.13mSv$ in 2008, $0.43{\pm}0.20mSv$ in 2009, and $0.33{\pm}0.85mSv$ in 2010. The average dose of radiation exposure in hospital K by age group was 13.39mSv for age 20 to 29, 8.37mSv for age 30 to 39, 1.19mSv for age 40 to 49, 0.28mSv for age 50 to 59, and 0.32mSv for age 60 to 69 The average dose of radiation exposure in hospital P by age group was 0.33mSv for age 20 to 29, 1.41mSv for age 30 to 39, 0.83mSv for age 40 to 49, 1.66mSv for age 50 to 59, and 1.12mSv for age 60 to 69. Moreover, the average radiation exposure to radiation-related workers over 3 year period by gender group in hospital K was $2.92{\pm}1.03mSv$ for male group and $0.94{\pm}0.93mSv$ for female group. The average radiation exposure over 3 year period by gender group in hospital P was $0.66{\pm}0.18mSv$ for male group and $1.80{\pm}0.60mSv$ for female group. Persons working in diagnostic radiology department received mean of $1.65{\pm}1.54mSv/year$, mean $1.17{\pm}0.82mSv/year$ in radiation oncology, mean $1.79{\pm}1.42mSv/year$ at nuclear medicine department and mean $0.99{\pm}0.51mSv/year$ at other departments. Radiation exposure was higher than that of other departments(p<0.05). Doctors and technologists received higher radiation exposure (mean $1.75{\pm}1.17mSv/year$, $1.60{\pm}1.39mSv/year$ each) than other workers(p<0.05). Measurement and evaluation of radiation exposure in radiation-related workers should be widely conducted accurately and consistently in the radiation-related occupational setting so that people in these occupational settings are more aware of the risk from radiation exposure, and thus give more attention and caution to decrease radiation exposure. It would be essential to minimize accumulated radiation dose in the radiation-related occupational setting in order to maintain and improve the health of radiation-related workers.

• BMB Reports
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• 제44권8호
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• pp.512-516
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• 2011

Establishment of immortalized human dermal papilla cells (DPCs) retaining the characteristics of DPCs would be a great help for hair researchers. We recently established a simian virus 40T (SV40T)-transformed human DP cell line (SV40TDPC). However, the cell line senesced around passage 25 and ceased proliferation. In this study, we introduced the human telomerase reverse transcriptase (hTERT) gene into SV40T-DPC and established an immortalized human DP cell line. The cell line, SV40T-hTERT-DPC, did not induce tumors when inoculated into nude mice. SV40T-hTERT-DPC maintained morphology of early passage DPCs, expressed markers of DPCs, and retained responses to Wnt/${\beta}$-catenin and bone morphogenic protein (BMP) signaling pathways known to be required for hair-inducing activity of DPCs. The data strongly suggest that SV40T-hTERT-DPC retains many characteristics of human DPCs in vivo without malignant transformation.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제11권6호
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• pp.2118-2123
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• 2010

Korean individual occupational exposure control is focused on the retrospective service to the over-exposed person by the reading of personal dosimeter. Since the radiophamaceuticals using in the nuclear medicine department are uncontained radiation sources, the potential exposure at working environment is very high. Moreover, a patient remains radioactive for hours or even days after the administration of a radiopharmaceutical for diagnosis or treatment. Thus, the proper working environmental exposure control must be established and executed to protect not only the affiliated employees, but also guardians accompanying patients and temporarily visiting public from the exposure by the patients. Japanese radiation protection law regulates working environmental radiation exposure by regularly measuring and filing the environmental dose for years. This study was aimed at measuring working environmental radiation dose in the nuclear medicine department of an university hospital located in Daejeon, Korea. We measured the accumulation radiation dose in air at 8 locations in the nuclear medicine department by using the same method as in Japan with glass dosimeters. The highest dose rate, 0.23 mSv per month, was measured at the waiting room, and the second one is at reception desk. Even though the doses were lower than the Korean constraint dose rate (0.3 mSv/week) at the boundary of the radiation controlled area, it was over the dose limit of public (1 mSv/y) and environment (0.25 mSv/y). Conclusionally, it was found that the new or additional procedure was necessary to less the exposure dose to the receptionist and guardians by the environmental radiation dose in the nuclear medicine department.

• Natural Product Sciences
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• 제10권3호
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• pp.129-133
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• 2004

Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect in nonmalignant hepatic cells. Using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed tumorigenic cell line (BNL SV A.8), we evaluated the effects of quercetin on cell proliferation and apoptosis. As the results, our present study demonstrated that quercetin had a selective growth inhibition in normal versus tumorigenic hepatic cells such that BNL SV A.8 cells were very sensitive to the quercetin-mediated cytotoxicity. In particular, as evidenced by the increased number of positively stained cells in the TUNEL assay, the induction of characteristic nuclear DNA ladders, and the migration of many cells to sub-G1 phase in the BNL SV A.8 cells, quercetin treatment more sensitively induced apoptosis in BNL SV A8 cells than in BNL CL.2 cells. Collectively, our findings suggest that quercetin can be approached as a potential agent that is capable of inducing selective growth inhibition and apoptosis of hepatic cancer cells.

• Asian-Australasian Journal of Animal Sciences
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• 제33권8호
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• pp.1339-1351
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• 2020

Objective: It is well recognized that beef cuts from a low quality grade are usually associated with tougher, drier and less flavorful. Thus, the present study aimed at investigating the combined effects of postmortem ageing and sous vide (SV) cooking followed by oven roasting or blowtorching on the eating quality of low quality grade Hanwoo beef striploins. Methods: Hanwoo beef striploins (quality grade 3) obtained from 36 month-old Hanwoo steers were used, and the samples were chiller aged for 0 and 14 d at 4℃. After ageing, the samples were prepared into 2.5-cm steaks which were then SV cooked at 55℃ for 5 h and then raised to 60℃ for 1 h, and thereafter the SV-cooked the steaks were further roasted in oven for 20 min (SV+OV) or blowtorched (SV+TC) for 2 min. The cooked samples were analyzed for microbiological quality, browning index, Wanrner-Bratzler shear force (WBSF), aroma flavor compounds and sensory properties. Results: The SV cooking significantly reduced the WBSF values in beef samples (p<0.05). Blowtorching after SV cooking led to a browner surface of the beef steaks (p<0.05). The samples treated with SV+OV or SV+TC exhibited higher levels of Maillard reaction-derived aroma flavor compounds such as; pyrazines and sulfur-containing compounds compared to those just SV cooked. More especially, the SV+OV- or SV+TC- treated samples presented significantly higher flavor and overall acceptability scores compared to those just SV cooked (p<0.05). Ageing beef for 14 d significantly improved the tenderness by reducing the WBSF and increasing the tenderness scores. Conclusion: Thus, the combination of postmortem ageing and SV cooking followed by additional treatments (blowtorching or oven roasting) could be used to improve the eating quality especially tenderness and flavor as well as overall acceptability of low grade Hanwoo beef.

• Journal of radiological science and technology
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• 제20권1호
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• pp.71-75
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• 1997

This study was Investigation that we will become aware of the scattering dose of duty station and TLD value of the radiation exposure by the radiation technologists based on the university hospital located in Kwang ju. The results are followings ; 1. The air of scattering dose in chest, when the number of objects are large, is 2.0 mR in P-A and 4.6 mR in Lat. at the back of X-ray tube 2. Radiologists, radiation exposure in duty station Is 0.22 mSv to 1.96 mSv in general examination, 0.22 mSv to 1.12 mSv in contrast and special examination, 0.26 mSv to 30.96 mSv in angiography, and 0.22 mSv to 0.40 mSv in C.T 3. The value of workig condition reveals 85.5% in general examination, 6% in contrast and special examination, and 5.8% in C.T. When the annual exposure is over 20 mSv, it must be measured again according to ICRP public 60.

• Earthquakes and Structures
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• 제8권6호
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• pp.1299-1323
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• 2015

A model for reflection and refraction of magneto-thermoelastic SV-waves at the interface of two transversely isotropic and homogeneous solid half spaces under initial stress by applying classical dynamical theory of thermoelasticity is purposed. The reflection and refraction coefficients of SV-waves are obtained with ideal boundary conditions for SV-wave incident on the solid-solid interface. The effects of magnetic field, temperature and initial stress on the amplitude ratios after numerical computations are shown graphically with MATLAB software for the particular model.

• The Korean Journal of Pain
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• 제27권2호
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• pp.145-151
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• 2014

Background: The physician's hands are close to the X-ray field in C-arm fluoroscopy-guided pain interventions. We prospectively investigated the radiation attenuation of Proguard RR-2 gloves. Methods: In 100 cases, the effective doses (EDs) of two dosimeters without a radiation-reducing glove were collected. EDs from the two dosimeters-one dosimeter wrapped with a glove and the other dosimeter without a glove-were also measured at the side of the table (Group 1, 140 cases) and at a location 20 cm away from the side of the table (Group 2, 120 cases). Mean differences such as age, height, weight, radiation absorbed dose (RAD), exposure time, ED, and ratio of EDs were analyzed. Results: In the EDs of two dosimeters without gloves, there were no significant differences ($39.0{\pm}36.3{\mu}Sv$ vs. $38.8{\pm}36.4{\mu}Sv$) (P = 0.578). The RAD ($192.0{\pm}182.0radcm^2$) in Group 2 was higher than that ($132.3{\pm}103.5radcm^2$) in Group 1 (P = 0.002). The ED ($33.3{\pm}30.9{\mu}Sv$) of the dosimeter without a glove in Group 1 was higher than that ($12.3{\pm}8.8{\mu}Sv$) in Group 2 (P < 0.001). The ED ($24.4{\pm}22.4{\mu}Sv$) of the dosimeter wrapped with a glove in Group 1 was higher than that ($9.2{\pm}6.8{\mu}Sv$) in Group 2 (P < 0.001). No significant differences were noted in the ratio of EDs ($73.5{\pm}6.7%$ vs. $74.2{\pm}9.3%$, P = 0.469) between Group 1 and Group 2. Conclusions: Proguard RR-2 gloves have a radiation attenuation effect of 25.8-26.5%. The radiation attenuation is not significantly different by intensity of scatter radiation or the different RADs of C-arm fluoroscopy.