• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.184-193
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• 2021

Background: The radionuclides released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident 9 years ago are still being monitored by various research teams and the Japanese government. Comparison of different surveys' results could help evaluate the exposure doses and the mechanism of radiocesium behavior in the urban environment in the area. In this study, we clarified the relationship between land use and temporal changes in the ambient dose rates (air dose rates) using big data. Materials and Methods: We set a series of 1 × 1 km² meshes within the 80 km zone of the FDNPP to compare the different survey results. We then prepared an analysis dataset from all survey meshes to analyze the temporal change in the air dose rate. The selected meshes included data from all survey types (airborne, fixed point, backpack, and carborne) obtained through the all-time survey campaigns. Results and Discussion: The characteristics of each survey's results were then evaluated using this dataset, as they depended on the measurement object. The dataset analysis revealed that, for example, the results of the carborne survey were smaller than those of the other surveys because the field of view of the carborne survey was limited to paved roads. The location factor of different land uses was also evaluated considering the characteristics of the four survey methods. Nine years after the FDNPP accident, the location factor ranged from 0.26 to 0.49, while the half-life of the air dose rate ranged from 1.2 to 1.6. Conclusion: We found that the decreasing trend in the air dose rate of the FDNPP accident was similar to the results obtained after the Chernobyl accident. These parameters will be useful for the prediction of the future exposure dose at the post-accident.

• Vascular Specialist International
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• v.34 no.4
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• pp.88-93
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• 2018

Purpose: This study aimed to compare surgical revisions and balloon angioplasty after surgical thrombectomy on thrombosed dialysis access as a first event. Materials and Methods: Records of patients undergoing creation of arteriovenous grafts (AVGs) at the Gachon University Gil Medical Center between March 2008 and February 2016 were reviewed. Among them, patients who underwent treatment on first-time thrombotic occlusion after AVG creation were identified. Outcomes were primary, primary-assisted, and secondary patency. The patency was generated using the Kaplan-Meier method, and patency rates were compared by log-rank test. Results: A total of 59 de novo interventions (n=26, hybrid interventions; n=33, surgical revisions) for occlusive AVGs were identified. The estimated 1-year primary patency rates were 47% and 30% in the surgery and hybrid groups, respectively. The estimated primary patency rates were not different between the two groups (log-rank test, P=0.73). The Kaplan-Meier estimates of 6 and 12 months for primary-assisted patency rates were 68% and 57% in the surgery group and 56% and 56% in the hybrid group. The Kaplan-Meier estimates of 12 and 24 months secondary patency rates were 90% and 71% in the surgery group and 79% and 62% in the hybrid group. There were no differences in the estimated primary-assisted and secondary patency rates between the two groups. Conclusion: Our results showed no significant difference between the two groups in terms of primary patency (P=0.73), primary-assisted patency (P=0.85), and secondary patency (P=0.78). However, percutaneous transluminal angioplasty can give more therapeutic options for both surgeons and patients.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.99-105
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• 2000

Objective: The objective of this study was to compare results of the macroscopic one-layer vasovasostomy with those of microscopic one-layer vasovasostomy and to analyze the change of semen parameters according to the interval of vasal obstruction. Method and Materials: Between March 1987 and December 1997, we performed 121 vasovasostomies using modified one-layer technique with loupe magnification (macroscopic vasovasostomy) or microscope. Among the 68 could be followed post-operatively, 37 patients were treated by macroscopic technique with loupe, and 31 patients by microscopic technique. We compared rates of anatomical patency (sperm count above than $10{\times}10^{6}$/ml) and pregnancy of macroscopic vasovasotomy with those of microscopic vasovasostomy. Patency and pregnancy rates according to vasal obstructive interval were also examined. Results: The patency rates of macroscopic and microscopic technique were 86.5% and 87.1%, and pregnancy rates of macroscopic and microscopic technique were 64.9% and 67.7%. There was no statistical significance between these two methods (p>0.05). The pregnancy rates and sperm motility were decreased if more than 10 years had elapsed following vasectomy (p<0.05). Conclusion: We found little difference in success rates resulting from macroscopic and microscopic vasovasostomy and the former had the advantage of reduced cost and a lower operator skill level. In post-operative semen analysis, the sperm motility was the most probable factor associated with vasal obstructive interval.

• Progress in Medical Physics
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• v.25 no.2
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• pp.65-71
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• 2014

A Varian Portal Dosimetry system was compared to an isocentrically mounted MapCHECK 2 diode array for volumetric modulated arc therapy (VMAT) QA. A Varian TrueBeam STx with an aS-1000 digital imaging panel was used to acquire VMAT QA images for 13 plans using four photon energies (6, 8, 10 and 15 MV). The EPID-based QA images were compared to the Portal Dose Image Prediction calculated in the Varian Eclipse treatment planning system (TPS). An isocentrically mounted Sun Nuclear MapCHECK 2 diode array with 5 cm water-equivalent buildup was also used for the VMAT QAs and the measurements were compared to a composite dose plane from the Eclipse TPS. A ${\gamma}$ test was implemented in the Sun Nuclear Patient software with 10% threshold and absolute comparison at 1%/1 mm (dose difference/distance-to-agreement), 2%/2 mm, and 3%/3 mm criteria for both QA methods. The two-tailed paired Student's t-test was employed to analyze the statistical significance at 95% confidence level. The average ${\gamma}$ passing rates were greater than 95% at 3%/3 mm using both methods for all four energies. The differences in the average passing rates between the two methods were within 1.7% and 1.6% of each other when analyzed at 2%/2 mm and 3%/3 mm, respectively. The EPID passing rates were somewhat better than the MapCHECK 2 when analyzed at 1%/1 mm; the difference was lower for 8 MV and 10 MV. However, the differences were not statistically significant for all criteria and energies (p-values >0.05). The EPID-based QA showed large off-axis over-response and dependence of ${\gamma}$ passing rate on energy, while the MapCHECK 2 was susceptible to the MLC tongue-and-groove effect. The two fluence-based QA techniques can be an alternative tool of VMAT QA to each other, if the limitations of each QA method (mechanical sag, detector response, and detector alignment) are carefully considered.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.325-333
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• 1997

Recent evidence indicates that growth factors modulate response of mammary epithelial cells to environmental stress. The objective of this study was to examine the cellular and biochemical responses of mammary tissue to environmental stress caused by artificial mastitis. For experimental a, pp.oach, toxins of most mastitis causing organisms(Staph. aureus or Strep. agalactiae) and heat stress(42$^{\circ}C$) were artificially exposed to mammary tissue. Effects of these environmental stresses on cell growth, cell death and heat shock protein synthesis were examined. Lactating mammary tissure were cultured under basal medium(DMEM) su, pp.emented with insulin(10$\mu\textrm{g}$/ml) and aldosterone(1$\mu\textrm{g}$/ml). All treatment groups in heat stress at 42$^{\circ}C$ incubation significantly decreased DNA synthesis rates in comparison with those at 39$^{\circ}C$(P<0.05), however, these decreased DNAa synthesis rates were recovered by addition of adenosine(10$\mu$M) and IGFI(10ng/ml). Similar results were obtained when tissue growth rates were measured by DNA content/tissue. Strep. agalactiae toxin did not significantly decreased DNA content/tissue in comparison with no treatment of bacterial toxin with or without heat stress, however, tended to decrease DNA contents/tissue without heat stress. In the fluorography analysis, heat stress(42$^{\circ}C$ incubation) slightly increased 35S-methoionine labelled 70kd protein synthesis. These results indicate that environmental stress caused by artificial mastitis slightly decreased mammary growth or mammary size, however, these results could be recovered by addition of adenosine and IGF-I.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8491-8494
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• 2016

Purpose: To compare unsatisfactory rates and detection of abnormal cervical cytology between conventional cytology or Papanicolaou smear (CC) and liquid-based cytology (LBC). Materials and Methods: A total of 23,030 cases of cervical cytology performed at King Chulalongkorn Memorial Hospital during 2012-2013 were reviewed. The percentage unsatisfactory and detection rates of abnormal cytology were compared between CC and LBC methods. Results: There was no difference in unsatisfactory rates between CC and LBC methods (0.1% vs. 0.1%, p = 0.84). The detection rate for squamous cell abnormalities was significantly higher with the LBC method (7.7% vs. 11.5%, p < 0.001), but those for overall abnormal glandular epithelium were similar (0.4% vs. 0.6%, p = 0.13). Low grade squamous lesion (ASC-US and LSIL) were more frequently detected by the LBC method (6.1% vs. 9.5%, p < 0.001). However, there was no difference in high gradd squamous lesions (1.1% vs. 1.1%, p = 0.95). When comparing between types of glandular abnormality, there was no significant difference the groups. Conclusions: There was no difference in unsatisfactory rates between the conventional smear and LBC. However, LBC could detect low grade squamous cell abnormalities more than CC, while there were similar rates of detection of high grade squamous cell lesions and glandular cell abnormalities.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.327-333
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• 2015

Previously, all-sky airglow images observed at Shigaraki ($34.9^{\circ}N$, $136.1^{\circ}E$), Japan, during 2004 and 2005 were analyzed in relation to those observed at Mt. Bohyun ($36.2^{\circ}N$, $128.9^{\circ}E$) for a comparison of their gravity wave characteristics (Kim et al. 2010). By applying the same selection criteria of waves and cloud coverages as in the case of Mt. Bohyun all-sky images, we derived apparent wavelengths, periods, phase velocities, and monthly occurrence rates of gravity waves at Shigaraki in this study. The distributions of wavelengths, periods, and speeds derived for Shigaraki were found to be roughly similar to those for Mt. Bohyun. However, the overall occurrence rates of gravity waves at Shigaraki were 36% and 34% for OI 557.7 nm and OH Meinel band airglow layers, respectively, which were significantly higher than those at Mt. Bohyun. The monthly occurrence rates did not show minima near equinox months, unlike those for Mt. Bohyun. Furthermore, the seasonal preferential directions that were clearly apparent for Mt. Bohyun were not seen in the wave propagation trends for Shigaraki. These differences between the two sites imply different origins of the gravity waves near the Korean peninsula and the Japanese islands. The gravity waves over the Japanese islands may originate from sources at various altitudes; therefore, wind filtering may not be effective in causing any seasonal preferential directions in the waves in the airglow layers. Our analysis of the Shigaraki data supports recent theoretical studies, according to which gravity waves can be generated from in situ sources, such as mesosphere wind shear or secondary wave formation, in the mesosphere.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.1
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• pp.121-132
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• 2011

Removal rates of $NO_3$-N and TN in the free-water surface wetland system during winter; December, January, February and March, spring and fall; April, May, October and November, and summer; Jun, July, August and September were investigated. The system was established on floodplain in the downstream reach of the Gwangju Stream in 2008. It measures 50 meters in length and 5.5 meters in width. Iris pseudacorus L. grown in pots for about two years were planted in the system. The water stream was funneled in by gravity and its effluent was discharged back in. Volumes and water quality of inflow and outflow were analyzed from December 2008 to November 2010. The inflow was averaged approximately 350 $m^3/day$ and hydraulic residence time was about 3 hours. Average influent and effluent $NO_3$-N concentration was 3.75 and 3.35 mg/L, respectively and $NO_3$-N retention was amounted to 10.6%. Influent and effluent TN concentration were averaged 4.93 and 4.30 mg/L, respectively and TN abatement reached to 12.9%. One-way ANOVA statistics claimed that the average removal rates of $NO_3$-N and TN during winter, spring and fall, and summer were not always the same (p<0.001). The t-Tests of three pairs among $NO_3$-N removal rates of winter, spring and fall, and summer illustrated that the removal rates of winter ($5.04{\pm}1.94$), spring and fall ($10.53{\pm}2.24$), and summer ($18.61{\pm}2.26$) were significantly different each others (p<0.001). Among TN removal rates, the three pairs of t-Tests of three seasons showed that the removal rates of winter ($5.21{\pm}2.51$), spring and fall ($11.71{\pm}3.12$), and summer ($21.53{\pm}4.86$) were significantly different from each others (p<0.001).

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.72-79
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• 2015

Electricity can be generated when the natural gas passes through a turbo-expander pressure reduction system at natural gas pressure reduction stations. Efficiency of the turbo-expander depends on the ratio of the natural gas flow rates to the design flow rate of the turbo-expander. Therefore, the optimal conditions for the operation of the pressure reduction system can be determined by controlling the natural gas flow rates. In this study, we have calculated the electric energy generation depending on the natural gas flow rates at the two low-pressure reduction stations when the pressure of the natural gas is reduced from 17.5 bar to 8.5 bar and have found the optimal conditions for the turbo-expander pressure reduction system through the comparison with the calculation results. The turbo-expander generates the electric power efficiently for the high natural gas flow rates which variations are slight. The determined design flow rate of the turbo-expander has the highest coverage of the natural gas flow rates. The electricity generation is calculated as much as 9 MW(B station) and 12 MW(D station) at each pressure reduction station.

• Journal of agricultural medicine and community health
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• v.49 no.2
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• pp.93-101
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• 2024

Objective: This study compared the status of chronic diseases among immigrants and the Korean population. Methods: This study was conducted on 153 immigrants living in Gwangju Metropolitan City in 2022. For comparison, 459 Koreans were selected using the 2021 Korea National Health and Nutrition Examination Survey (KNHANES). A survey was conducted on the management status of hypertension, diabetes, and hyperlipidemia using a questionnaire. Results: Immigrants were significantly more likely to have hypertension (50.3% vs. 24.2%, p<0.001) and diabetes (19.0% vs. 11.5%, p=0.002) than Koreans. In awareness, immigrants had significantly lower rates of hypertension (57.1% vs. 73.0%, p=0.031) and hyperlipidemia (immigrants 25.4% vs. 44.5%, p=0.006). In treatment rates, immigrants had significantly lower rates of hypertension (40.3% vs. 69.4%, <0.001) and hyperlipidemia (17.9% vs. 39.6%, p=0.003). In control rates, immigrants had significantly lower rates of hypertension (18.2% vs. 62.2%, <0.001) than Koreans. Conclusions: Chronic diseases are common among immigrants, but awareness, treatment, and control rates are low, so education and prevention policies are critical to improving immigrants' access to medical care and raising awareness.