• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.725-733
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• 2023

The Korea Institute of Radiological and Medical Sciences has started a radiation epidemiological study, titled "Korean Radiation Worker Study," to evaluate the health effects of occupational exposure to radiation. As a part of this study, we investigated the methodologies and results of reconstructing organ-specific absorbed doses based on personal dose equivalent, H_p(10), reported from 1984 to 2019 for 20,605 Korean radiation workers. For the organ dose reconstruction, representative exposure scenarios (i.e., radiation energy and exposure geometry) were first determined according to occupational groups, and dose coefficients for converting H_p(10) to organ absorbed doses were then appropriately taken based on the exposure scenarios. Individual annual doses and individual cumulative doses were reconstructed for 27 organs, and the highest values were observed in the thyroid doses (on average 0.77 mGy/y and 10.47 mGy, respectively). Mean values of individual cumulative absorbed doses for the red bone marrow, colon, and lungs were 7.83, 8.78, and 8.43 mSv, respectively. Most of the organ doses were maximum for industrial radiographers, followed by nuclear power plant workers, medical workers, and other facility workers. The organ dose database established in this study will be utilized for organ-specific risk estimation in the Korean Radiation Worker Study.

• BMB Reports
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• v.47 no.6
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• pp.324-329
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• 2014

Regulators of G-protein signaling (RGS) proteins regulate certain G-protein-coupled receptor (GPCR)-mediated signaling pathways. The GABAB receptor ($GABA_BR$) is a GPCR that plays a role in the stress response. Previous studies indicate that acute immobilization stress (AIS) decreases RGS4 in the prefrontal cortex (PFC) and hypothalamus (HY) and suggest the possibility of a signal complex composed of RGS4 and $GABA_BR$. Therefore, in the present study, we tested whether RGS4 associates with $GABA_BR$ in these brain regions. We found the co-localization of RGS4 and $GABA_BR$ subtypes in the PFC and HY using double immunohistochemistry and confirmed a direct association between $GABA_{B2}R$ and RGS4 proteins using co-immunoprecipitation. Furthermore, we found that AIS decreased the amount of RGS4 bound to $GABA_{B2}R$ and the number of double-positive cells. These results indicate that $GABA_BR$ forms a signal complex with RGS4 and suggests that RGS4 is a regulator of $GABA_BR$.

• Investigative Magnetic Resonance Imaging
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• v.24 no.3
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• pp.123-131
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• 2020

Purpose: Joint label fusion (JLF) is a popular multi-atlas-based segmentation algorithm, which compensates for dependent errors that may exist between atlases. However, in order to get good segmentation results, it is very important to set the several free parameters of the algorithm to optimal values. In this study, we first investigate the feasibility of a JLF algorithm for prostate segmentation in MR images, and then suggest the optimal set of parameters for the automatic prostate segmentation by validating the results of each parameter combination. Materials and Methods: We acquired T2-weighted prostate MR images from 20 normal heathy volunteers and did a series of cross validations for every set of parameters of JLF. In each case, the atlases were rigidly registered for the target image. Then, we calculated their voting weights for label fusion from each combination of JLF's parameters (r_pxy, r_pz, r_sxy, r_sz, β). We evaluated the segmentation performances by five validation metrics of the Prostate MR Image Segmentation challenge. Results: As the number of voxels participating in the voting weight calculation and the number of referenced atlases is increased, the overall segmentation performance is gradually improved. The JLF algorithm showed the best results for dice similarity coefficient, 0.8495 ± 0.0392; relative volume difference, 15.2353 ± 17.2350; absolute relative volume difference, 18.8710 ± 13.1546; 95% Hausdorff distance, 7.2366 ± 1.8502; and average boundary distance, 2.2107 ± 0.4972; in parameters of r_pxy = 10, r_pz = 1, r_sxy = 3, r_sz = 1, and β = 3. Conclusion: The evaluated results showed the feasibility of the JLF algorithm for automatic segmentation of prostate MRI. This empirical analysis of segmentation results by label fusion allows for the appropriate setting of parameters.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.39-49
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• 2023

This study data were collected from 217 nursing students in J city to analyze major satisfaction and awareness of the importance of practice and performance of nursing students' practice at the public health center, and to identify improvement plans for the practice contents of the health center. The collected data was analyzed using SPSS WIN 25.0, and the research results showed that there was a positive correlation (r=.55, p<.001) between major satisfaction and public health center clinical practice performance, and the sub-factors of performance It showed positive correlation with all (r=.41~.54, p<.001). In particular, among the sub-factors, Internal growth through practice and Correlation with the actual application of theory were highly correlated (r=.54~.56, p<.001). In order to improve nursing students' satisfaction with their major, theoretical study should be preceded, and through area analysis, in order to obtain satisfaction through identity and internal growth of nursing students while practicing health center practice, practice instructors during health center practice Establish various networks, do our best to communicate smoothly with nursing students, and strive to present opinions through meetings with practice institutions before and after practice to improve the community health center practice environment. Also, nursing college students In order for the public health center practice to be carried out smoothly, practice guidance instructors drew improvement points that nursing college students need prior learning related to practice before practicing health center practice.

• 대한예방의학회:학술대회논문집
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• 2001.10a
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• pp.343-344
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• 2001

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.272-288
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• 1998

The purpose of this study was to investigate the acute(4 hrs) and repeated-dose(6 hrs a day, 5 days a week, 8 weeks) toxic effects of 1-bromopropane(1-BP) on Sprague-Dawley (SD) rats which were treated by inhalation. The results were as follows ; 1. The median lethal concentration($LC_{50}$) was estimated 14,374 ppm(confidence limit 95% ; 13,624~15,596 ppm) in acute inhalation. Abnormal clinical signs related to the 1-BP were not observed with the acute inhalation dose. Gross findings of necropsy revealed no evidence of specific toxicity related to the 1-BP. 2. By sub-acute inhalation the body weights of male and female were significantly reduced(p<0.001) by the dose of 1,800 ppm compared with control group, while the relative weights of liver were significantly increased(p<0.001) in both sexes. However there were no significant variation in food consumption, urine biochemistry, hematology and blood biochemistry for the exposed rats compared with the control rats. Abnormal clinical signs and gross findings of necropsy related to the 1-BP were not shown. No toxicologic lesions were observed by the histopathological test.

• Journal of Environmental Health Sciences
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• v.48 no.6
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• pp.298-305
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• 2022

Background: The concentration of air pollutants as measured by the Air Quality Monitoring System (AQMS) is not an accurate population exposure level since actual human activities and temporal and spatial variability need to be considered. Therefore, to increase the accuracy of exposure assessment, the population should be considered. However, it is difficult to obtain population data due to limitations such as personal information. Objectives: The existing population defined in this study is the number of people in each region's grid. The purpose is to provide a methodology for evaluating exposure to PM_2.5 through existing population data provided by the National Geographic Information Institute. Methods: The selected study period was from October 26 to October 28, 2021. Using PM_2.5 concentration data measured at the Sensor-based Air Monitoring Station (SAMS) installed in Guro-gu and Wonju-si, the concentration for each grid was estimated by applying inverse distance weights through QGIS version 3.22. Considering the existing population, population-weighted average concentration (PWAC) was calculated and the exposure level of the population was compared by region. Results: The outdoor PM_2.5 concentration as measured through the SAMS was high in Wonju-si on all three days. Wonju-si showed an average 22% higher PWAC than Guro-gu. As a result of comparing the PWAC and outdoor PM_2.5 concentration by region, the PWAC in Guro-gu was 1~2% higher than the observed value, but it was almost the same. Conversely, observations of Wonju-si were 10.1%, 11.3%, and 8.2% higher than PWAC. Conclusions: It is expected that the Geographic Information System (GIS) method and the existing population will be used to evaluate the exposure level of a population with a narrow activity radius in further research. In addition, based on this study, it is judged that research on exposure to environmental pollutants and risk assessment methods should be expanded.

• Journal of Environmental Science International
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• v.29 no.1
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• pp.109-117
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• 2020

Asthmatics are more susceptible to fine particulate matters (PM_2.5), compared to the general population. It has been reported that indoor PM_2.5 is mainly generated by combustion of fossil fuels, meat or fish In particular, asthmatics are known to be more susceptible to indoor PM_2.5 because 65~95% of child or adult asthmatics stay inside the house. Thus, understanding the association between indoor activity patterns and variations in indoor PM_2.5 levels is important. The purpose of this study is to determine the distribution of hourly indoor PM_2.5 concentrations in asthmatics' homes, and to evaluate its association with pan-frying cooking activity patterns, the most common PM_2.5 emission related activity. From November 2017 to February 2018, real-time PM_2.5 concentrations were measured in the living room of each asthmatic's house (n = 35) for three weeks at 1 minute intervals. At the same time, self-reported daily activity patterns, hourly proportion (%) of cooking activities, were also recorded every hour over three weeks for each patient. In this study, we provided quantitative evidence that the distribution patterns of indoor hourly PM_2.5 concentrations were associated with indoor cooking activities, especially in the homes of adult asthmatics. In addition, we observed that PM_2.5 emitted by pan-frying could maintain even over up to 2 hour lagtime.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.1-10
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• 2023

Urbanization and industrialization associated with rapid economic development have resulted in air pollution in urban areas, which adversely affects human health and the environment around the world. Growing awareness of the health effects of airborne particulate matter (PM) has led to the emergence of urban greening as a promising eco-friendly, nature-based solution to reduce the concentration of PM (especially PM_2.5) to which individuals are exposed, thereby promoting public health. In this review, we highlight fundamental insights about PM and recent research on the ability of urban greening to capture PM. Reports from the scientific literature on PM published from 1992 to 2021 were retrieved from Google Scholar. Here, we explore some of the main complex relationships between leaf traits and the ability to retain PM for research or management to optimize greenspaces.

• Journal of Preventive Medicine and Public Health
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• v.56 no.2
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• pp.128-144
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• 2023

Objectives: The health system reform process is highly political and controversial, and in most cases, it fails to realize its intended goals. This study was conducted to synthesize factors underlying the failure of health system reforms. Methods: In this systematic review and meta-synthesis, we searched 9 international and regional databases to identify qualitative and mixed-methods studies published up to December 2019. Using thematic synthesis, we analyzed the data. We utilized the Standards for Reporting Qualitative Research checklist for quality assessment. Results: After application of the inclusion and exclusion criteria, 40 of 1837 articles were included in the content analysis. The identified factors were organized into 7 main themes and 32 sub-themes. The main themes included: (1) reforms initiators' attitudes and knowledge; (2) weakness of political support; (3) lack of interest group support; (4) insufficient comprehensiveness of the reform; (5) problems related to the implementation of the reform; (6) harmful consequences of reform implementation; and (7) the political, economic, cultural, and social conditions of the society in which the reform takes place. Conclusions: Health system reform is a deep and extensive process, and shortcomings and weaknesses in each step have overcome health reform attempts in many countries. Awareness of these failure factors and appropriate responses to these issues can help policymakers properly plan and implement future reform programs and achieve the ultimate goals of reform: to improve the quantity and quality of health services and the health of society.