• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.591-600
• /
• 2018

The objective of this study was to determine the changes in phytoplankton and long-term water quality of Juksan-Weir in Yeongsan River that took place between April 2010 and December 2015. The number of species used in this study was 288, which consisted of 6% of Cyanophyta, 26% of Bacillariophyta, 53% of Chlorophyta and the others (15%). The standing crops of phytoplankton ranged from $500cells{\cdot}mL^{-1}-29,950cells{\cdot}mL^{-1}$ with an average of $7,885cells{\cdot}mL^{-1}$. At the two site, 20 dominant genera of found. The dominant genera were 6 of Bacillariophyta, 6 of Cyanophyta, 7 of Chlorophyta and 1 of Cryptophyta. The most dominant genus among the phytoplankton was Stephanodiscus sp. (Total 59%, each 54% and 63%). The most dominant genus among the Cyanophyta was Microcystis sp., which had a cell abundance ratio of 17%. The results of two sites were 21% and 13%, and the upstream was higher than the downstream.

• Journal of Life Science
• /
• v.29 no.2
• /
• pp.173-180
• /
• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.2
• /
• pp.173-180
• /
• 2021

Purpose: The purpose of this study was to evaluate the retentive characteristics of the additional attachments used with implant bar attachment under repeated insertion/removal cycles. Materials and methods: The newly developed attachment and the commercially available attachment were investigated: ADD-Lock (AL), Locator blue (LB). Two fixtures were placed parallel to each other on the custom lower mounting, and patrix of each attachment was fixed to the fixture. Also, the matrix of each attachment was placed on the opposing upper mounting. A universal testing machine was used to measure the retentive force during initial, 100, 250, 500, 1000, 2000, and 2500 repeated insertion/removal cycles. Wear and deformation of the attachment s were observed by scanning electron microscopy (SEM). Mann-Whitney U test (α=.05) and wilcoxon signed-rank test (α=.05) were performed to compare retentive force between each group and before and after 2500 repeated insertion/removal cycles. Results: In terms of initial retentive force and retentive force after 2500 repeated insertion/removal cycles, the AL group (15.24 ± 1.46 N and 9.74 ± 1.16 N) showed significantly smaller values than the LB group (43.53 ± 12.39 N and 22.99 ± 4.77 N) (P<.05). Also, in the loss of retentive force, the AL group (5.50 ± 1.08 N, 36.08%) showed a smaller value than the LB group (20.54 ± 11.89 N, 47.19%) (P<.05). Based on SEM analysis, The AL group showed noticeable wear and deformation in the patrix and the LB group in the matrix. Conclusion: Locator showed a higher initial retentive force than newly developed attachment, while the loss of retentive force was also higher. Both additional attachments are considered to have sufficient retentive force after repeated insertion/removal cycles.

• Journal of Korean Classical Literature and Education
• /
• no.39
• /
• pp.137-180
• /
• 2018

This article examines the constitutional characteristics of the works in the "Shinbi Apartment" (Mysterious Apartment) series produced by Tooniverse, a domestic animation channel, and considers the meaning of the contents of the ghoststory (鬼神談). The "Shinbi Apartment" series is a horror animation for children. It was produced for the first time in Korea and recorded high ratings. Additionally, it is different from Japanese horror animations that were dubbed and broadcast in Korea in terms of composition and narrative direction, and it succeeds in the form and direction of the traditional Korean ghost story. "Shinbi Apartment - The Secret of Ghost Ball" enriches narrative stories by embracing the structure of the "female ghost story" in traditional ghost stories while following the form of ghosts that suddenly pop up in the daily routines of contemporary ghost stories. The ghost's shape, which has a bizarre and unpredictable aspect, embodies the ghost as the object of fear that modern horror stories intend. However, it does not stop there, but puts the attention on the hero who focuses on the emerging ghost and listens and communicates with it, placing the emphasis of the story on communication, understanding, forgiveness, and reconciliation. The structure and contents of the unique story of "The Secret of Ghost Ball" contribute to the transformation of the ghost into a subject of friendliness and entertainment, not merely as one of shock, fear, and anxiety. Additionally, as the concept of "child" is being created, the custom of modernity, which deals with the story of ghosts in the dimension of teaching and edification, is also manifested in "The Secret of Ghost Ball." In other words, through the figure of the devil, it is to continue the lesson of the story by revealing the adventure, the courage necessary for the "child," and the boundaries for substance and appearance. The "Shinbi Apartment" series has also contributed to the success of ghosts as commercial contents. The structure of the story and its characters have been actively used as educational tools and toys for children. It can be said that ghost culture contributed to this popularization by establishing a base for enjoying ghosts for amusement and entertainment.

• The Journal of Korean Philosophical History
• /
• no.56
• /
• pp.151-180
• /
• 2018

Since the completion of the theories on human ethics and moral had been established to pursue by Confucian thinkers like Confucius and Mencius, they generally had agreed to present the basic principles for human education which every human could be the sage. In these principles for human ethics and morality there is on the premise that the knowledge about your own ethical and that the completion of the so-called act(爲) and learning(學). They had given to us that how to get a goal for the ethical and moral lives there are several academic oriented methodology will have act and learning set. In the point of achieving complete figures which act and learning for good society, there was named the sage(聖). This concept sage has two major types. One is on for the political figures that completed, and the other one is for the realm of academic side. Confucian as above mentioned the moral human being is equipped with a complete personality and political ability to make man and society perfect. Confucius has been understood as a complete human being. Yes, ideal for these two types of figures will be fulfilled in some way? They take a mystical ability to a priori or a posteriori, such as human effort can reach the sage. There are many thinkers are obvious and logical answer for this major problem in the system of confucian philosophy I have been trying. About the sage(聖), inherently natural learning(生知) occur to the position sage or knowledge (學知), can lead to there are two of the doctrine for that problem. With the study of learning and knowledge on human beings and real society the two systems concerned together. In fact, the main content of the "Analects of Confucius" we have a set of ethical and moral values not the benevolent conversation about Jin(仁) and his disciples a steady emphasis but on in praise of learning (學) for. However, at the time in Han Tang(漢唐) Han Wi(韓愈) and Wang Chung(王充), according to such thinkers the sage is already a priori determined, cannot be reached by human effort. But At the beginning of the Neo-Confucianism, Cheng I(程?) for the pioneer this Song(宋) scholars, regarding this issue could rebirth the thought that every human could be the sage through the learning as the pre-Chin(先秦) times.

• Journal of Nutrition and Health
• /
• v.55 no.6
• /
• pp.670-683
• /
• 2022

Purpose: To provide the primary data on dietary guidelines for the management of obesity, we analyzed the intake rate of food groups and dish groups according to obesity and age. Data were obtained from the Korea National Health and Nutrition Examination Survey (KNHANSE, 2013-2018). Methods: This study analyzed the data of 21,184 adults aged 19-64 years, obtained from the KNHANSE 2013-2018. The 24-hour recall was performed and the food groups were classified into six representative food groups (grains, meat·fish·eggs·legumes, vegetables, fruits, milk and dairy, and oil and sugar), and 'alcohol' and 'others'. The dish groups were classified into a total of twenty-four types. Results: The normal group included 9,004 subjects (42.5%), while the obese group had 12,180 subjects (57.5%). The food groups showing significant differences according to obesity were grains (p < 0.001), meat/fish/egg/legumes (p < 0.001), and vegetables (p < 0.001); similar results were obtained in both male and female. Comparing the intake rate of food groups and dish groups targeting only the obese group according to age, the food groups showing significance between the obese group and the normal group were grains (p < 0.001) and vegetables (p < 0.001), with significantly increased intake in both genders. Considering the dish groups, significant increases were determined for stews (p < 0.001), seasoned vegetables (p < 0.001), and kimchi (p < 0.001) in male, and for rice (p < 0.001), seasoned vegetables (p < 0.001), kimchi (p < 0.001), and rice cakes (p < 0.001) in female. Conclusion: The results of this study determined that the intake ratio of food and dish groups differs by age in obese adults. We believe that our results can be used as primary data for forming dietary guidelines for obese adults in the future.

• Journal of Korean Academy of Dental Administration
• /
• v.5 no.1
• /
• pp.31-37
• /
• 2017

Recently interest in infection control is increasing in hospitalsnfection control has become more important in the overall health care practiceental hospital also requires thorough infection control. There are various kinds of vectormedical clothing. Contaminated clothing of a hospital staff can be a vector of nosocomial infecton. actual case of nosocomial infecton caused by contaminated medical clothing, nursing students were measuring contamination levels of uniforms and pathogenic microorganism wdetected in front of the uniform and pocket. There is also a high risk of exposure to contamination in the dental hospital. We conducted a study to enhance awareness about infection and proper clothing management by comparing before and after contamination of clothing caused by aerosols produced during scaling. Subjects were scaling operators' uniforms in the department of dental hygiene, K University located in Daejeon. Before scaling, the uniform was sterilized by autoclavecaling was performed times in the same place (an average of 60 minutes per person, a total of 180 minutes). ive parts of the uniform (sleeves, chest, belly, thigh, edge of pants) contracted Rodak-plate for 15 seconds. After incubating the contacted Rodak-plate at 37℃ incubator, contamination levels by measuring the number of colonies. As a result, all parts increased number of colonies. ontamination order chestedge of pants thigh belly sleeves. Increase rate of colonies was also high in the order chest edge of pants thigh belly sleeves. This study showed seriousness of clothing contaminationcaused by aerol produced during scalingcontamination of clothing can be a path to nosocomial infecton. According to th study, infection control for clothing as well as dental instruments should be implemented and thorough infection control training needed for dental staff. In further researches, practical infection prevention supplementing clothing management method.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.4
• /
• pp.225-236
• /
• 2019

BACKGROUND: Hydroponics is one of the methods for evaluating plant production using the inorganic nutrient solutions, which is applied under the artificial light conditions of plant factory system. However, the application of the conventional inorganic nutrients for hydroponics caused several environmental problems: waste from culture mediums and high nitrate concentration in plants. Organic nutrients are generally irrigated as a supplementary fertilizer for plant growth promotion under field or greenhouse conditions. Hydroponic culture using organic nutrients derived from the agricultural by-products such as dumped stems, leaves or immature fruits is rarely considered in plant factory system. Effect of organic or conventional inorganic nutrient solutions on the growth and nutrient absorption pattern of green and red leaf lettuces was investigated in this experiment under fluorescent lamps (FL) and mixture Light-Emitting Diodes (LEDs). METHODS AND RESULTS: Single solution of tomatoes (TJ) and kales (K) deriving from agricultural by-products including leaves or stems and its mixed solution (mixture ration 1:1) with conventional inorganic Yamazaki (Y) were supplied for hydroponics under the plant factory system. The Yamazaki solution was considered as a control. 'Jeockchima' and 'Cheongchima' lettuce seedlings (Lactuca sativa L.) were used as plant materials. The seedlings which developed 2~3 true leaves were grown under the light qualities of FL and mixed LED lights of blue plus red plus white of 1:2:1 mixture in energy ratio for 35 days. Light intensity of the light sources was controlled at 180 μmol/㎡/s on the culture bed. The single and mixture nutrient solutions of organic and/or inorganic components which controlled at 1.5 dS/m EC and 5.8 pH were regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Number of unfolded leaves of the seedlings grown under the single or mixed nutrient solutions were significantly increased compared to the conventional Y treatment. Leaf extension of 'Jeockchima' under the mixture LED radiation condition was not affected by Y and YK or YTJ mixture treatments. SPAD value in 'Jeockchima' leaves exposed by FL under the YK mixture medium was approximately 45 % higher than under conventional Y treatment. Otherwise, the maximum SPAD value in the leaves of 'Cheongchima' seedlings was shown in YK treatment under the mixture LED lights. NO₃-N contents in Y treatment treated with inorganic nutrient at the end of the experiment were up to 75% declined rather than increased over 60 % in the K and TJ organic treatment. CONCLUSION: Growth of the seedlings was affected by the mixture treatments of the organic and inorganic solutions, although similar or lower dry weight was recorded than in the inorganic treatment Y under the plant factory system. Treatment Y containing the highest NO₃-N content among the considered nutrients influenced growth increment of the seedlings comparing to the other nutrients. However effect of the higher NO₃-N content in the seedling growth was different according to the light qualities considered in the experiment as shown in leaf expansion, pigmentation or dry weight promotion under the single or mixed nutrients.

• Radiation Oncology Journal
• /
• v.19 no.2
• /
• pp.171-180
• /
• 2001

Purpose : Expression of TIMP, intrinsic inhibitor of MMP, is regulated by signal transduction in response to genotoxins and is likely to be an important step in metastasis, angiogenesis and wound healing after ionizing radiation. Therefore, we studied radiation mediated TIMP expression and its mechanism in head and neck cancer cell lines. Materials and Methods : Human head and neck cancer cell lines established at Asan Medical Center were used and radiosensitivity $(D_0)$, radiation cytotoxicity and metastatic potential were measured by clonogenic assay, n assay and invasion assay, respectively. The conditioned medium was prepared at 24 hours and 48 hours after 2 Gy and 10 Gy irradiation and expression of TIMP protein was measured by Elisa assay with specific antibodies against human TIMP. hTIMP1 promoter region was cloned and TIMP1 luciferase reporter vector was constructed. The reporter vector was transfected to AMC-HN-1 and -HN-9 cells with or without expression vector Ras, then the cells were exposed to radiation or PMA, PKC activator. EMSA was peformed with oligonucleotide (-59/-53 element and SP1) of TIMP1 promoter. Results : $D_0$ of HN-1, -2, -3, -5 and -9 cell lines were 1.55 Gy, 1.8 Gy, 1.5 Gt, 1.55 Gy and 2.45 Gy respectively. n assay confirmed cell viability, over $94\%$ at 24hrs, 48hrs after 2 Gy irradiation and over 73% after 10 Gy irradiation. Elisa assay confirmed that cells secreted TIMP1, 2 proteins continuously. After 2 Gy irradiation, TIMP2 secretion was decreased at 24hrs in HN-1 and HN-9 cell lines but after 10 Gy irradiation, it was increased in all cell lines. At 48hrs after irradiation, it was increased in HN-1 but decreased in HN-9 cells. But the change in TIMP secretion by RT was mild. The transcription of TIMP1 gene in HN-1 was induced by PMA but in HN-9 cell lines, it was suppressed. Wild type Ras induced the TIMP-1 transcription by 20 fold and 4 fold in HN-1 and HN-9 respectively. The binding activity to -59/-53, AP1 motif was increased by RT, but not to SP1 motif in both cell lines. Conclusions : We observed the difference of expression and activity of TIMPs between radiosensitive and radioresistant cell line and the different signal transduction pathway between in these cell lines may contribute the different radiosensitivity. Further research to investigate the radiation response and its signal pathway of TIMPs is needed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.18 no.2
• /
• pp.95-106
• /
• 1998

A study was made to estimate the economic level(Necon.) of mineral nitrogen and a cutting frequency for the dry matter production of reed canarygrass(Phalaris arundinacea L.) in uncultivated rice paddy during the harvested years in 1993~1995. Annual mineral nitrogen was applied at the levels of 0, 90, 180, 270 and 360 kg $ha^{-1}$ in 3 cuttings, 0, 120, 240, 360 and 480 kg $ha^{-1}$ in 4 cuttings, and 0, 150, 300, 450 and 600 kg $ha^{-1}$ in 5 cuttings, respectively. The results were summarized as follows; 1. The dry matter yields of all cutting frequencies in 1993 were significantly higher than in the other hay years. Mean dry matter yield were 14.40, 13.88 and 15.98 tons $ha^{-1}$ in 3, 4 and 5 cuttings, respectively. 2. Significantly higher matter yields were obtained as 15.37 and 15.80 tons $ha^{-1}$ at the level of 120 kg $ha^{-1}\;cut^{-1}$ in 3 and 4 cuttings, and 14.02~14.08 tons $ha^{-1}$ levels of 90~120 kg $ha^{-1}$ in 5 cuttings, respectively. 3. Higher efficiencies of dry matter production in response to mineral nitrogen application were recorded as 29.7 kg at level of 90 kg $ha^{-1}\;yr^{-1}$ in 3 cuttings, 19.6 kg at level of 240 kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 20.1 kg at level of 150 kg $ha^{-1}\;yr^{-1}$ in 5 cuttings, respectively. 4. Significantly higher matter yields appeared as 5.02 tons $ha^{-1}$ at 2nd cut in 3 cuttings, 3.94~4.37 tons $ha^{-1}$ at 2nd and 3rd cut in 4 cuttings, and 3.81~3.58 tons $ha^{-1}$ at 2nd and 3rd cut in 5 cuttings, respectively. 5. The highest values of relative dry matter yield were 40.4% for 2nd cut in 3 cuttings, 34.9% for 3rd cut in 4 cuttings, and 31.5% for 2nd cut in 5 cuttings, respectively. 6. The estimated marginal dry matter yields(Ymar.) were 13.8~14.7 tons $ha^{-1}$ at ranges of economic N level of 228.5~291.9 kg $ha^{-1}\;yr^{-1}$ in 3 cuttings, 13.8~14.2 tons $ha^{-1}$ at ranges of 293.5~335.7 kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 12.2~12.8 tons $ha^{-1}$ at ranges of 237.5~302.5 kg $ha^{-1}\;yr^{-1}$ in 5 cuttings, respectively. 7. Maximun dry matter yields(Ymax.) were 17.0 tons at the level of limiting N(Nmax.) of 558.9 kg $ha^{-1}\;yr^{-1}$ in 3 cuttings, 16.1 ton at level of limiting N of 531.4 kg $ha^{-1}\;yr^{-1}$ in 4 cuttings, and 13.9 ton at level of limiting N of 546.3 kg $ha^{-1}\;yr^{-1}$ in 5 cuttings, respectively. 8. Economic N level in all cuts were in the ranges of 42.6~123.8 kg $ha^{-1}$ in 3 cuttings, 27.3~144.1 kg $ha^{-1}$ in 4 cuttings, and 9.3~159.4 kg $ha^{-1}$ in 5 cuttings, respectively. 9. The proper cutting frequency for matter production of reed canarygrass was 3 cuttings during the h harvested years in 1993~1995, due mainly to the higher efficiency of N for the dry matter production.