• Korean Journal of Microbiology
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• v.27 no.4
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• pp.357-365
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• 1989

Induction conditions for autolysis and autoplast formation of thermophilic Clostridium thermohydrosulfuricum were studied. The cells in the initial exponential growth phase were well autolysed in Tris-HCl buffer or inorganic buffers containing univalents, such as $K^{+}$ and $Na^{+}$ , and chemicals such as cysteine-HCl, sorbitol and glycerol. Meanwhile, autolysis induction was slightly inhibited by divalents, such as $Mg^{2+}, Mn^{2+}, Ca^{2+}, Ni^{2+}$, and strongly by divalents, such as $Fe^{2+}, Cu^{2+}$ and citric acid. The autolysis was stimulated when the cells were grown in the medium containing ampicillin that inhibites cell wall synthesis, meanwhile, it was slightly inhibited by nucleic acids and protein synthesis inhibitors. The optimal pH and temperature for the induction of autolysis were 7.5 and $60^{\circ}C$, respectively. On the other hand, the cells were autoplasted without lysozyme treatment during autolysis due to the stabilization of protoplasmic membrane in the presence of divalents such as $Mg^{2+}, Mn^{2+}, Ca^{2+}, Ni^{2+}$. Autoplast formation was mostly induced at $37^{\circ}C$ in 50mM Tris-HCl buffer (pH 7.5) containing 20 mM $MgCl^{2}$ and 0.3 M glycerol, and in the late exponential growth phase growing cell.

• Polymer(Korea)
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• v.35 no.4
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• pp.337-341
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• 2011

To expand the viewing angle of vertical alignment liquid crystal display (VA-LCD), a wide-band compensation film has been newly developed. VA-LCD needs a retardation film with improved oblique viewing property. The retardation film for VA-LCD has been fabricated by solvent casting and subsequent drawing triacetylcellulose (TAC) containing optical additives. Here, optical birefringence and wavelength dispersion of the retardation film strongly depend on the chemical structures of optical additives. Utilizing quantum mechanical computation, the polarizing anisotropy of retardation film was calculated with respect to additives. It is also realized that the wavelength dispersion of polarizing anisotropy depends on the type and location of substituent to the selected main isomer. When two propionates are substituted to the meta position of the selected main isomer, the wavelength dispersion of polarizing anisotropy shows the most gentle slop, which is well matched with the experimental results. The most gentle slop of wavelength dispersion means that the viewing angle characteristics of LCD are less influenced according to the wavelength of light source of LCD, and it's possible to make better image quality than the present level.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.635-640
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• 2018

The study conducted a Focus Group Interview (FGI) on college students to identify single-person households and Solitary Deaths of single-person households recognized by college students. This can be provided as basic data to address problems in single-person households and social problems such as future youth solitary death and will contribute to building a social safety net. This study conducted FGI to analyze data for five fourth graders majoring in social welfare. In the case of involuntary independent living, the high poverty and unemployment rate of single-person households was cited as the cause of economic instability, housing problems and emotional relationship formation. He said that he thinks about young loneliness because he has vague fears about what happens in the media and what can happen to them. As the number of young single-person households will inevitably increase in the coming months and economic difficulties are the biggest problem and the biggest cause of young solitude, institutional support is needed first, especially for housing costs.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.65-76
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• 2019

The purpose of this study was to investigate breast cancer its menopause in South Korean adult women using data from the seventh Korea national health and nutrition examination survey(KNHANES VII-2) 2017. The subjects were 3,414 people in total. The Data were analyzed by frequency, ${\chi}^2$ test and multiple logistic regression analysis using SPSS complex samples Win 25 program. According to the age of the subjects, breast cancer was 1.7% higher in women aged 50~59 years than aged 40~49 years, and 1.7% was significantly more frequent in women who had no drinking frequency than in almost everyday. Menopausal age was significantly higher in women under 44 years of age with breast cancer than in those over 50 years of age. According to menopause, postmenopausal breast cancer was 1.7% more than before menopause. When adjusted for age and alcohol drinking frequency, premenopausal adult women in Korea had significantly lower breast cancer frequency by 0.03 compared with postmenopausal women. Based on these results, it is important to pay attention to the management of breast cancer in young women aged 44 years or younger and multidisciplinary efforts are needed to reduce the ever-increasing prevalence of breast cancer.

• Health Policy and Management
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• v.31 no.1
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• pp.74-90
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• 2021

Background: It is getting important to improve the oral health status of the elderly because oral health status may affect their health status of the whole body. In this respect, we aimed to explore the association of oral health status and behavior factors with self-rated health status by sex. Methods: Using the data from the 7th Korea National Health and Nutrition Examination Survey for health surveys and oral examinations (2016-2018), we analyzed a total of 3,070 people aged 65 or older (men: 1,329; women: 1,741). Our dependent variable, self-rated health status, was divided into two groups: not good (bad and very bad) and good (very good, good, and fair), whereas our independent variables of interest were oral health status and behavior factors. In addition to descriptive analysis and the Rao-Scott chi-square test, reflecting survey characteristics, we conducted hierarchical multivariable logistic regression analyses adjusted for socio-demographics and health status and behavior factors. All analyses were stratified by sex. Results: The proportion of people having 'not good' self-rated health was 36.5% in women but 24.5% in men. In a model adjusted for all covariates, the self-rated health status showed significant association with the self-rated oral health status. For example, in men, the risk of having 'not good' self-rated health was high in people having 'poor' (odds ratio [OR], 5.31; 95% confidence interval [CI], 2.34-12.03) self-rated oral health status and in those having 'fair' (OR, 4.03; 95% CI, 1.68-9.70) in comparison with those having 'good' self-rated oral health status. Dental status regarding speaking difficulty seemed to be very important in influencing self-rated health status. For instance, in women, compared to people having 'no discomfort' speaking difficulty, the risk of having 'not good' self-rated health was high in people having 'not bad' (OR, 1.60; 95% CI, 1.14-2.24) and 'discomfort' (OR, 1.79; 95% CI, 1.30-2.47) speaking difficulty. The covariates significantly associated with the risk of having 'not good' self-rated health were: physical activity, chronic disease, stress, and body mass index in both sexes; health insurance type and drinking only in men; and economic activity only in women. Conclusion: Oral health status and behavioral factors were associated with self-rated health status among the elderly, differently by sex. This suggests that public health policies toward better health in the elderly should take their oral health status and oral health behaviors into account in a sex-specific way.

• Journal of Ethics
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• no.80
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• pp.1-30
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• 2011

Confucianism and Buddhism were compatible in the period of Goryeo Dynasty. And then, the rulers worshiped Confucianism and repressed the religious activity of the Buddhist monk in the early years of the Joseon Dynasty. But King Sejong planed to bring reconciliation between Confucianism and Buddhism. Especially on the ceremonies of mourning and sacrificial rituals, he always performed the two religious style. The reason of sticking to his amicable consciousness is as follows. Firstly, he thinks that both the theory of Confucianism and the religious spirit of Buddhism are very important for the building up the foundation of his Dynasty. Secondly, his mind has been of a same faith cure on the incurable disease. Therefor, when the Royal family is taken ill he must pray to Buddha for recovery from the first stage. Thirdly, he regards social conditions to be the most important and respect for man's life and dignity for the purpose of beneficent administration. But Joseon's government line was the anti-Buddhist policy. So, the policy came in the wake of a debate among King Sejong and Confucian government officials. However his harmonious mind was unchanged between Confucianism and Buddhism. After all, in the last phase of his life he was deeply religious on Buddhism. I think that King Sejong's amicable consciousness could make a contribution to overcome religious conflicts and to create a new political cultural form in the modern society

• Journal of Environmental Impact Assessment
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• v.33 no.5
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• pp.228-251
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• 2024

It is clear that the implementation of Total Pollution Load Management (TPLM) has contributed to the improvement of river water quality in Korea. However, it is also true that the TPLM has focused on point source pollution management, with limitations in addressing non-point source pollution. This study examined the issues of the current TPLM from the perspective of non-point source pollution, which is closely related to high-flow conditions, by analyzing Load Duration Curves (LDC) using water quality and flow data collected over the past four years from 21 sub-watersheds in the Geum River Basin. Since the current TPLM is based on water quality predictions using a static water body model that applies the average flow of the dry season, we found that the reduction in loads required under actual flow conditions could be up to 140 times greater than under the reference flow condition, indicating that load amounts under high-flow conditions are not reflected. Additionally, there were abnormal correlations between discharge loads and water quality in several sub-watersheds, and illogical situations arose where compliance with allocated loads did not align with achieving the target water quality. While the causes of such abnormal and illogical situations are diverse and complex, this study highlights the need for rational reflection of non-point source loads under high-flow conditions in water quality modeling. As a solution, we propose the application of watershed models and dynamic water body models.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.84-89
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• 2017

This study was carried out to investigate residue dissipation of fluquinconazole and flusilazole in field-sprayed tomatoes during greenhouse cultivation and processing. The test pesticide, fluquinconazole+flusilazole 8.5 (7+1.5)% SC, was sprayed onto the tomatoes growing in a greenhouse according to Korea preharvest intervals and then samples were collected on 0 (3 hours after spraying), 1, 3, 5 and 7 days after last application for decline test. For processing test, tomatoes collected at harvest on 5 day after last application were processed to puree and juice. Limits of quantitation of fluquinconazole and flusilazole were 0.005 mg/kg in both tomatoes and their processed products. Recoveries for validation of the analytical methods for fluquinconazole and flusilazole in tomatoes and their processed products ranged from 74.8 to 97.5%. Biological half-lives of fluquinconazole and flusilazole in tomatoes under greenhouse conditions found to be 5.2 and 6.4 days, respectively. Average persistent residue levels of fluquinconazole and flusilazole were 37.34 and 79.53% after washing, 8.95 and 28.75% in filtrates after boiling, 3.58 and 14.66% in puree, and 3.34 and 13.52% in juice, respectively. These results indicated that the test pesticide residues on tomatoes could be largely removed through washing and boiling.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.129-138
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• 2012

We investigated an ecological impact of drought simulated by discharge depletion on the water quality and benthic diatom community in the indoor experimental channel. As artificial substrates slide-glass was installed in acrylic channel for 16 days. Channels were supplied continuously with eutrophic lake water with a discharge rate of 6 L $min^{-1}$ in duplication during the colonized period. And then during the discharge depletion period, three discharge rates were provided: NDF (No depletion of flow rate (Control): 6 L $min^{-1}$), LDF (Low depletion of flow rate: 3 L $min^{-1}$) and HDF (High depletion of flow rate: 1 L $min^{-1}$). Environmental factors in the water, such as suspended solid, Chl-$a$ and nutrients concentration, were measured with periphytic algae including AFDM (ash free dry matter), Chl-$a$ concentration and cell density at 1-day intervals. Light intensity increased significantly with discharge depletion (F=229.5, p= 0.000). $NH_4$-N concentration was highest at HDF. Suspended solid in outflowing water decreased at HDF (88%), LDF (97%) and NDF (99%), compared to inflowing water (100 %). Chl-$a$ in substrates increased more than two times at LDF and HDF than NDF (F= 8.399, p=0.001). Also AFDM and benthic diatom density increased significantly at LDF and HDF than NDF (F=9.390, p=0.001; F=6.088, p=0.007). In all experimental groups, $Aulacoseira$ $ambigua$, $Achnanthes$ $minutissima$ and $Aulacoseira$ $granulata$ were dominant species accounting for greater than 10% of benthic diatom density. The most dominant species, $A.$ $ambigua$ was highest at LDF, followed by HDF and NDF (F=8.551, p=0.001). In conclusion, the effect of drought simulated by discharge depletion in an artificial stream ecosystem caused significant changes on water quality and benthic diatom biomass. This result provides a useful data to understand the effect of draught on stream ecosystem in situ.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.104-111
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• 1976

The experiment was tested with fruit of 5 astringent cultivars (Chungdo-Bansi, Sagoksi, Euisung-Bolbansi and Gyungsan-bansi) and was carried out to investigate effects of harvest time of fruit and fruit sizes on the removal of astringency and the practical utilization with Chungdo-Bansi was conducted. 1. Soluble tannin content was decreased in all cultivars as fruit was ripening and soluble tannin content at last harvest time was reduced about one half, as contrasted it's content at first harvest time and it showed that the times required of the removal of astringency was gradually shortened. 2. In soluble tannin contents was small fruit size was significantly higher than that of large fruit size. The times for the removal of astringency was required longer small fruit size than large fruit size. 3. In the changes of hardness according to fruit sizes, hardness of large fruit size was decreased rapider than that of small fruit size. This tendency became similar during and after the removal of astringency. 4. According to fruit sizes, sugar content of large fruit size was more amount than that of small fruit size During and after the removal of astringency, reduction of sugar content showed more rapidly large fruit size than small fruit size. 5. Results of the practical utilization in Chungdo-Bansi showed the promising market-ability and persimmons treated by carbon dioxide was increased more income than that treated by $CaC_2$.