• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.332-343
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• 2005

The purpose of this study was to evaluate the influence of soft-start light curing on contraction stress and hardness of composite resin. Composite resin mold was cured using the one-step continuous curing method with three difference light sources; conventional halogen light curing for 40 seconds at $400\;mw/cm^2$, plasma arc light curing for 6 seconds at $1300\;mW/cm^2$ and LED light curing for 10 seconds at $7The purpose of this study was to evaluate the influence of soft-start light curing on contraction stress and hardness of composite resin. Composite resin mold was cured using the one-step continuous curing method with three difference light sources; conventional halogen light curing for 40 seconds at . For the soft-start curing method ; 2 seconds light exposure at $650\;mW/cm^2$ followed by 3 seconds at $1300\;mW/cm^2$ and exponential increase with 5 seconds followed by 10 seconds at $700\;mW/cm^2$ were used. Contraction stress was measured using strain gauge method and Vickers hardness was measured 24 hours after polymerization at the top and bottom of specimens. Resin-acrylic interfaces were observed using a scanning electron microscope(SEM). The results of present study can be summarized as follows: 1. Contraction stresses at 10 min after polymerization were significantly reduced with the soft-start curing both in plasma and LED light sources(P<0.05). 2. Plasma light curing with soft-start resulted in not only the lowest contraction stress, but also the lowest hardness(P<0.05) 3. LED light curing with soft-start showed lower contraction stress than the one-step continuous halogen and LED light curing(P<0.05). 4. Microhardness of specimens cured by LED light with soft-start was equivalent to that of cured by the one-step continuous halogen and LED light(P>0.05). 5. Curing by LED light with soft-start and conventional halogen light resulted in better marginal sealing than plasma light and one-step LED light curing.

• Radiation Oncology Journal
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• v.22 no.2
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• pp.138-141
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• 2004

Purpose : We have previously reported that human glioblastoma cells are sensitized to radiation-induced death after their exposure to trichostatin A (TSA), a histone deacetylase inhibitor (HDAC-1), prior to the irradiation. We aimed to measure the magnitude of the radiosensitizing effect of TSA in human head and neck cancer cell lines. Materials and Methods : Human head and neck cancer cell lines, HN-3 and HN-9, were exposed to 0, 50, 100, and 200 nM TSA for 18 hr prior to irradiation. Then, the TSA-treated cells were irradiated with 0, 2, 4, 6, and 8 Gy, and cell survival was measured by clonogenic assay. Results : Pre-irradiation exposure to TSA was found to radiosensitize HN-3 and HN-9 cell lines. In HN-9 cells, the fraction surviving after 2 Gy (SF2) was significantly reduced by treatment of TSA at concentration as low as 50 nM. However, a treatment with 200 nM TSA was required to significantly decrease SF2 in the HN-3 cell line. SER of pre-irradiation treatment with 200 nM TSA was 1.84 in HN-3 and 7.24 in HN-9, respectively. Conclusions : Our results clearly showed that human head and neck cancer cell lines can be sensitized to ionizing radiation by pre-irradiation inhibition of histone deacetylase (HDAC) using TSA, and that this potentiation might well be a general phenomenon.

• Journal of Ginseng Research
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• v.30 no.3
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• pp.112-116
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• 2006

To investigate the protective effect of saponin from red ginseng extract, 2,3,7,8-tetrachlorodibenzo--dioxin (TCDD) was exposed to female guinea pigs and then femur weights was measured. Forty eight female guinea pigs ($820{\pm}25\;g$) were divided into 6 groups. Normal control group (NC) received vehicle and saline; only TCDD-treated group (TT) received TCDD ($5.0\;{\mu}g/kg$, single dose) intraperitoneally; pretreated group of saponin 10 (PE 10) received 10 mg/kg of saponin i.p. for 4 weeks from 1 week before TCDD-exposure; pretreated group of saponin 20 (PE 20) also received 20 mg/kg of saponin i.p. for 4 weeks from 1 week before TCDD-exposure. While, post-treated group of saponin 10 (CE 10) received 10 mg/kg of saponin i.p for 3 weeks after TCDD-exposure. Post-treated group of saponin 20 (CE 20) received 20 mg/kg saponin i.p for 3 weeks after TCDD-exposure. Body weight of TT group was significantly decreased after TCDD-exposure. However, body weight in all saponin-treated groups increased throughout the experimental period, although the increasing rate was slower than that of NC group. Body weights of PE 10 and 20 groups showed more higher increase than those of CE groups during the experimental period. Decrease of femur weights in female guinea pigs by TCDD intoxification was significantly recovered by the saponin treatment. Decrease of $Ca^{2+}$ level of femurs in female guinea pigs exposed TCDD also recovered by the treatment of saponin from red ginseng extract. Especially, PE20 group showed the highest increase of the $Ca^{2+}$ level in femur among the saponin treated groups. These results suggest that ginseng saponin might be a useful protective agent against femur damage caused to decrease of $Ca^{2+}$ by TCDD.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.3
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• pp.53-65
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• 2013

In Korea recently the consumption of coffee has been drastically increased and majority of people who are more than $20^{th}$ are drinking more than a cup of coffee every day. Nowadays coffee a kind of essential items in modern urban society. As the popularity of the coffee is increasing, As the coffee consumption is growing, the studies on coffee also have been increased. Many of the studies on coffee were focused on the consumer attitudes, coffee shops and franchise coffee shops, and coffee components or ingredients. As the products of the coffee are becoming diverse, the consumers of coffee also becoming diverse. There was a study showing that coffee has variety of types, and that motivations and attitudes for coffee consumption are different depend on demographic statistics such as age and life styles. On this study main focus was life style and consumer's motivation on coffee consumption. For this study the survey was conducted on the people living in Seoul City and Kyengkido from March 1, 2013 to March 31, 2013. 600 questionnaires were distributed and 480 were collected and 470 were used for analysis of this study. The statistics program used in this study was SPSS. The method used in the analysis wee factors analysis test, reliability test, validity test, t-testy, One-Way ANOVA, and regression analysis. In this study according to the factor analysis, the life styles were classified the following six categories ; wellbeing pursuit, taste pursuit, atmosphere pursuit, dine-out pursuit, instant pursuit, and economic value pursuit. The factors of coffee consumption motivation were 6; wellbeing consumption motivation, changing mood consumption motivation, social consumption motivation, habitual consumption motivation, and emotional consumption motivation. The demographic factors used in this study were age, marital status, occupation, educational background, residence, income, and eating-out expenses. The hypothesis used in this study were two. The first hypo-thesis was whether the coffee consumption was affected by the life styles. The second hypo-thesis was whether there was any statistical differences on the motivation of coffee consumption according to the characteristics of life style. The outcome of this study demonstrated that life styles had partial impact on coffee consumption motivations. According to the characteristics of the life style, except for the habitual consumption motivation, all the other factors showed statistical differences on coffee consumption motivations according the characteristics of life styles.

• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.176-187
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• 2015

In this study, we hypothesized that the size of wintering crane population would change due to the climate factors. We assumed that wintering population size would differ by climate values in January, which is the coldest period in year. Especially, White-naped cranes were able to choose wintering site between Cheorwon and other alternative place where snow coverage had low influence, differing from Red crowned cranes. For this reason, we predicted the population size of White-naped cranes would fluctuate according to the extent of snow coverage in Cheorwon. Therefore we used snow coverage data based on MODIS and climate data from KMA (Korea Meteorological Administration) that are generally used. We analyzed the crane's population size in Cheorwon in January from 2002 to 2014. The temperature in the Cheorwon increased from 2002 to wintering period in 2007~ 2008 and went down, showing the lowest temperature in 2011~ 2012. With this phenomenon, warmth index showed the similar pattern with temperature. Amount of newly accumulated snow (the amount of snow that fallen from 0:01 am to 11:29 pm in a day) was low after 2002, but rapidly increased in 2010~ 2011 and 2011~ 2012. The area of snow coverage rapidly declined from 2002 to 2005~ 2006 but suddenly expanded in wintering period in 2009~ 2010 and 2010~ 2011. Wintering population size of the White-naped cranes decreased as snow coverage area increased in January and the highest correlation was found between them, compared to the other climatic factors. However, the number of individuals of Red crowned cranes had little relationship with general climate factors including snow cover range. Therefore it seems that population size of the Red crowned crane varied by factors related with habitat selection such as secure roosting site and area of foraging place, not by climatic factors. In multiple regression analysis, wintering population of White-naped cranes showed significant relationship with logarithmic value of snow cover range and its period. Therefore, it suggests that the population size of the White-naped crane was affected by snow cover range n wintering period and this was because it was hard for them to find out rice grains which are their main food items, buried in snow cover. The population size variation in White-naped cranes was caused by some individuals which left Cheorwon for Izumi where snow cover had little influence on them. The wintering population in Izumi and Cheorwon had negative correlation, implying they were mutually related.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.158-163
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• 2014

In this study, two commercial PCR and ELISA test kits were examined for identification of eight animal species (beef, pork, chicken, duck, turkey, goat, lamb, and horse) from raw meat and meat products in Korea. The detection limit in RAW meat ELISA kit$^{(R)}$ on three types of meat samples blended with beef, pork and chicken, demonstrated that all meat species were differentiable down to 0.2%. RAW meat ELISA kit$^{(R)}$ on animal species resulted in differentiation rate of 94.5% for beef, 93.3% for pork, 90% for lamb, and 100% for chicken, duck, turkey, goat, and horse. In contrast, Powercheck Animal Species ID PCR kit$^{TM}$ resulted in 100% specificity at 0.05% limit of detection for all meat species. The detection limit of Cooked Meat ELISA kit$^{(R)}$ on mixed meat samples heat-treated with different temperatures and times, resulted in 0.1% for all heat-treated mixed meat except for chicken at 1.0%. Additionally, ELISA kit on sixty meat products resulted in specificity of 31.8% for ham, 13.6% for sausages, and 12.5% for ground processed products, and relatively low rate for more than 2 types of mixed meats. On the contrary, meat species differentiation using PCR kit showed higher percentage than that using ELISA kit$^{(R)}$: 50.0% for ham, 41.7% for sausages, and 28.6% for ground processed meat. Futhermore, PCR kit on 54 dried beef meats detected pork genes in 13 products whereas ELISA kit showed negative results for all products. Hence, the possibility of cross-contamination during manufacturing process was investigated, and it was found that identical tumblers, straining trays, cutters and dryers were used in both beef and pork jerky production line, suggesting the inclusion of pork genes in beef products due to cross-contamination. In this study, PCR and ELISA test kits were found to be excellent methods for meat species differentiation in raw meat and heat-processed mixed meat. However, lower differentiation rate demonstrated in case of meat processed products raised the possibility of inclusion of other species due to cross-contamination during manufacturing process.

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.39-54
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• 2000

Purpose: Dipyridamole stress myocardial perfusion SPECT could predict prognosis, however, long-term follow-up showed change of hazard ratio in patients with suspected coronary artery disease. We investigated how long normal SPECT could predict the benign prognosis on the long-term follow-up. Materials and Methods: We followed up 1169 patients and divided these patients into groups in whom coronary angiography were performed and were not. Total cardiac event rate and hard event rate were predicted using clinical, angiographic and SPECT findings. Predictive values of normal and abnormal SPECT were examined using survival analysis with Mantel-Haenszel method, multivariate Cox proportional hazard model analysis and newly developed statistical method to test time-invariance of hazard rate and changing point of this rate. Results: Reversible perfusion decrease on myocardial perfusion SPECT predicted higher total cardiac event rate independently and further to angiographic findings. However, myocardial SPECT showed independent but not incremental prognostic values for hard event rate. Hazard ratio of normal perfusion SPECT was changed significantly (p<0.001) and the changing point of hazard rate was 4.4 years of follows up. However, the ratio of abnormal SPECT was not. Conclusion: Dipyridamole stress myocardial perfusion SPECT provided independent prognostic information in patients with known and suspected coronary artery disease. Normal perfusion SPECT predicted least event rate for 4.4 years.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.202-206
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• 2014

In this study, the bacteriological survey was examined on ice creams at manufacturing factories in Korea during the summer season of 2011. The nineteen selected among 166 samples by preliminary test were collected from 11 different manufacturing factories in four major manufacturers in May 2011. Samples from ice milk, ice creams, sherbets, and non milk fat ice creams were tested for the total aerobic bacteria, coliform bacteria, and five food borne pathogens, respectively. The results showed that the coliforms including E. coli O157:H7, Salmonella spp., Staphylococcus aureus, Clostridium perfringens, and Listeria monocytogenes were not detected on all the ice creams. The total aerobic bacteria of the packed samples examined ranged between $2.5{\times}10^3$ and $5.5{\times}10^5cfu/g$. One ice cream, two sherbets, and four ice milk samples exceeded the acceptable limits of total aerobic bacteria according to the Korean standards for ice cream ($1.0{\times}10^5cfu/g$) and others ($5.0{\times}10^4cfu/g$). The levels of these microorganisms from ice creams were higher in three original equipment manufacturers than seven self-manufacturers. Three of ten ice creams (30.0%), three of six ice milks (50.0%), and one of two sherbets (50%) exceeded the acceptable limits of total aerobic bacteria, respectively. The personnel hygiene procedures with chocolate and vanilla chip addition from the manufacturing process were the main sources of the microbial contamination of stick-bar type ice creams when being produced in a factory. Improvement of the hazard analysis critical control points (HACCP) system should be introduced into the ice cream factory to improve the microbial quality of the ice cream products in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.2
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• pp.10-19
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• 2020

The park program can adeptly cope with the diversification of leisure needs in accordance with the changing times. The program also makes the relationship between the users and the park itself closer. For this reason, the Seoul Metropolitan Government has operated a variety of programs, beginning with the Botanical Class Program at the Namsan Outdoor Botanical Garden in 1997. The government additionally began to organize park programs by establishing the Park and Leisure Department and three Park Greenery Offices. However, research on park programs is mainly focused on park users. Therefore, this study intends to reveal the structure of the programs by studying the program operation. The specific purposes of this study are '1. Review the institutional characteristics that underlie the operation of the Park Program in Seoul by examining the relevant laws, the operation organizations, and the personnel composition, 2. Analyze the operation methods, such as procurement and the execution of the program, operation costs, and public-private cooperation methods, etc. 3. Analyze the composition and contents of the program from 2015 to 2017, and process and identify the relationship between the structure of the program operation and the program itself.' Summarizing the results obtained from the study, as far as the structure of the first program operation, the support laws were not systematic, but the operating organization was working to establish a system. The second characteristic of the operation is that most of the budget was funded by local governments, but the level of citizen involvement was low. Third, when we looked at the characteristics of the program, the number of programs increased, but they were focused on a specific theme and few programs actively used the park facilities. Based on the results, three tasks can be proposed. The first is that the 'Act on Parks and Green Spaces' should include the concepts and support for park programs. Second, there is a need to change from the ideas of the quantitative increase of programs to qualitative improvements. Lastly, it is necessary to reorganize the Green Seoul Bureau of the Seoul Metropolitan Government into a citizen-led and leisure-oriented organization to promote the park leisure culture. This study has significance, as it was conducted with a service provider, not a program user, unlike many previous park program-related studies. The results of this study will be able to contribute not only to the Seoul Metropolitan Government, but also to other local governments to suggest the direction of the management and the operation of the park for the consumer, and consequently, it will help prepare the long-term vision of parks as the closest leisure location for most citizens.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.149-156
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• 1995

Purpose : Since February 1991 a Prospective study for non-small cell lung cancer patients who underwent radical resection and had a risk factor of positive resection margin or regional lymph node metastasis has been conducted to evaluate the effect of MVP chemotherapy and radiotherapy on the pattern of failure, disease free and overall survival. and tolerance of combined treatment. Materials and Methods: Twenty nine patients were registered to this study until Sep. 1993; of these 26 received planned therapy Within 3 weeks after radical resection, two cycles of MVP(Mitomycin C $6mg/m^2,$ Vinblastin $6mg/m^2,$ Cisplatin $60mg/m^2$) chemotherapy was given with 4 weeks intervals. Radiotherapy (5040cGy tumor bed dose and 900cGy boost to high risk area) was started 3 to 4 weeks after chemotherapy. Results: One and two year overall survival rates were $76.5\%\;and\;58.6\%$ respectively. Locoregional failure developed in 6 patients$(23.1\%)$ and distant failure in 9 patients$(34.6\%)$ Number of involved lymph nodes, resection margin positivity showed some correlation with failure pattern but T-stage and N-stage showed no statistical significance. The group of patients who received chemotherapy within 2 weeks postoperatively and radiotherapy within 70 days showed lower incidence of distant metastasis. Postoperative combined therapy were well tolerated without definite increase of complication rate, and compliance rate in this study was $90\%$. Conclusion: 1) MVP chemotherapy showed no effect on locoregional recurrence, but appeared to decrease the distant metastasis rate and 2) combined treatments were well tolerated in all patients. 3) The group of patients who received chemotherapy within 2 weeks postoperatively and radiotherapy within 70days showed lower incidence of distant metastasis. 4) Addition of chemotherapy to radiotherapy failed to increase the overall or disease free survival.