• Radiation Oncology Journal
• /
• v.30 no.4
• /
• pp.182-188
• /
• 2012

Purpose: For recurrent esophageal cancer after primary definitive radiotherapy, no general treatment guidelines are available. We evaluated the toxicities and clinical outcomes of re-irradiation (re-RT) for recurrent esophageal cancer. Materials and Methods: We analyzed 10 patients with recurrent esophageal cancer treated with re-RT after primary definitive radiotherapy. The median time interval between primary radiotherapy and re-RT was 15.6 months (range, 4.8 to 36.4 months). The total dose of primary radiotherapy was a median of 50.4 Gy (range, 50.4 to 63.0 Gy). The total dose of re-RT was a median of 46.5 Gy (range, 44.0 to 50.4 Gy). Results: The median follow-up period was 4.9 months (range, 2.6 to 11.4 months). The tumor response at 3 months after the end of re-RT was complete response (n = 2), partial response (n = 1), stable disease (n = 2), and progressive disease (n = 5). Grade 5 tracheoesophageal fistula developed in three patients. The time interval between primary radiotherapy and re-RT was less than 12 months in two of these three patients. Late toxicities included grade 1 dysphagia (n = 1). Conclusion: Re-RT of recurrent esophageal cancer after primary radiotherapy can cause severe toxicity.

• Molecular & Cellular Toxicology
• /
• v.2 no.2
• /
• pp.120-125
• /
• 2006

Phenytoin is an anti-epileptic. It works by slowing down impulses in the brain that cause seizures. The recent microarray technology enables us to understand possible mechanisms of genes related to compounds which have toxicity in biological system. We have studied that the effect of a compound related to hepatotoxin in vitro system using a rat whole genome microarray. In this study, we have used a rat liver epithelial cell line WB-F344 and phenytoin as a hepatotoxin. WB-F344 was treated with phenytoin for 1 to 24 hours. Total RNA was isolated at times 1, 6 and 24h following treatment of phenytoin, and hybridized to the microarray containing about 22,000 rat genes. After analysis with clustering methods, we have identified a total of 1,455 differentially expressed genes during the time course. Interestingly, about 1,049 genes exhibited differential expression pattern in response to phenytoin in early time. Therefore, the identification of genes associated with phenytoin in early response may give important insights into various toxicogenomic studies in vitro system.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.16 no.4
• /
• pp.345-351
• /
• 2003

Due to increasing legal and market demands for safety in the automotive design process, the design of integrated seat is important more and mote because it should satisfy the conflict between stronger and lower weight for safety and environmental demands. In this study for crash simulations, the numerical simulations have been carried out using the explicit finite element program LS-Dyna according to the FMVSS 210 standard for safety test of seat. Since crash simulations are very time-consuming and a series of simulations that does not lead to a better result is very costly, the optimization method must be both efficient and reliable. As a result of that, statistical approaches such as design of experiments and response surface model have been successfully implemented to reduce time-consuming LS-Dyna simulations and optimize the safety and environmental demands together with nonlinear optimization algorithm. Design of experiments is used lot exploring the design space of maximum displacement and total weight and for building response surface models in order to minimize the maximum displacement and total weight of integrated seat.

• Journal of the Society of Naval Architects of Korea
• /
• v.40 no.5
• /
• pp.60-67
• /
• 2003

For risk or reliability assessment of ship structures against particular hazardous situations such as total loss or sinking due to hull girder collapse, the short-term based response analysis rather than the long-term response analysis is required to determine wave-induced bending moments when the ship encounters a storm of specific duration and with a specified small encounter probability. In the present study, the effects of operational condition and sea states on wave-induced bending moments of large merchant vessels are investigated. A series of the short-term response analyses for a hypothetical VLCC and a Capesize bulk carrier (CSBC) are carried out with varying operational condition and sea states which include ship speed, significant wave height and wave persistence time, using the linear-strip theory based program ABS/SHIPMOTION and the MIT sea-keeping tables. The computed results are also compared with the IACS design formula predictions. The results and insights developed from the present study are summarized.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2007.09a
• /
• pp.317-333
• /
• 2007

The Round-Robin Test (RRT) for ground response analysis was performed by Division of Geotechnical Earthquake Engineering of Korean Geotechnical Society. This research analyzed the influence of analysis methods on variation of ground response by using the results of this RRT. The analysis methods include equivalent linear analysis, non-linear analysis and effective stress analysis. A total of 5 teams among 12 teams applied two kinds of analysis methods. This research compared the results of these 5 teams and analyzed the variation of the results according to analysis methods. The compared results were shear stress-shear strain relation, transfer function, time history and the response spectrum of ground surface acceleration, peak ground acceleration, peak shear strain and maximum excess pore pressure ratio.

• Food Science and Preservation
• /
• v.15 no.1
• /
• pp.111-117
• /
• 2008

As part of studies on functional food development from the acorn (Quercus acutissima CARRUTHERS), this study investigated the antioxidant properties of the acorn using response surface methodology. Optimal extraction conditions were established by monitoring total phenol levels, electron donating ability, antioxidant ability and nitrite-scavenging action using response surface analysis under a central composite design. The extraction temperature varied in the $30-70^{\circ}C$, the extraction time between 1-5 h, and the solvent ratio was in the interval 5-25mL/g of sample. Extracted total phenols were highest at $57.91^{\circ}C$, 4.08 h, and 22.39 mL/g. This extraction was influenced by solvent ratio, but not by extraction time or temperature. Electron donating ability was found to be highest at $60.37^{\circ}C$, 2.85h, and 6.47 mL/g. The highest antioxidant level was 2.09 AI at $37.11^{\circ}C$, 1.67 h, and 18.84 mL/g, and this value was greatly influenced by all of extraction temperature, extraction time, and solvent ratio. Nitrite-scavenging ability was found to be highest at $47.07^{\circ}C$, 1.24h, and 19.55mL/g. Changes in nitrite-scavenging ability were most influenced by solvent ratio, followed by extraction temperature, but no influence of extraction time within the range tested was found.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.696-701
• /
• 2002

Optimal conditions for preparing of chitooligosaccharides from chitosan with cellulase was researched by response surface methodo-logy, Penicillium funiculosum derived cellulase was most effective for chitooligosaccharides production as the point of hydrolyzing activity and commercial utility. The result which measures the change of degrading ratio at time course, 10 hr reaction showed a exponential increase and after that time degrading ratio was not changed. The optimal conditions determined by response surface methodology with central composite design of total 26 species were $0.5\%$ of chitosan, 143 U enzyme, 49$^{\circ}C$ of reaction temperature, 13.2 hr of reaction time and pH 3.8. Major chitooligosaccharides produced from chitiosan on optimal conditions were dimer and trimer.

• The Journal of Industrial Distribution & Business
• /
• v.10 no.7
• /
• pp.83-89
• /
• 2019

Purpose - It is a very important issue for the Korean tourism industry to increase tourism revenue by attracting foreign tourists. Although Japanese tourists have been an important part of the Korean tourism industry for a long time, the level of tourist satisfaction including accommodation has been at the worst compared to other foreign visitors, which strongly requires concrete solutions. Therefore, this study focuses on improving the satisfaction level of Japanese visitors in the use of accommodation, and find out the influence of the managerial response. Research design, data, and methodology - In this study, customer review and managerial response of hotels in Seoul were collected from "Rakuten Travel" which is the most representative online travel agency in Japan. As a result of collecting data from 2016 to 2018, 6,190 customer reviews and 1,241 managerial responses from 120 hotels were used for analysis. In addition, information on the properties of 120 hotels, such as the number of rooms, classification, types of hotel facilities, types of room facilities, accessibility and prices, were collected. To test the hypotheses, moderated multiple regression analysis was conducted with SPSS 22.0. Results - It was found that only 25 sites, 20.8% of the total 120 sites, were implementing managerial response and average response rate was 66.42% among them. As a result of examining the main effects of the hotel attributes on the ratings, accessibility and price are confirmed as effective variables. We also found that the response rate has a significant moderate effect in both the accessibility and price. In other words, there was a significant difference in the influence of accessibility and price on the ratings depending on the response rate. Also, it was confirmed that the response rate is not a pure moderator variable but a quasi moderator variable. Overall, the evidences partially supported the hypothesis. Conclusion - It was possible to provide important suggestions to the hotel managers who were concerned about managing tourist satisfaction with accessibility problems. It was found that the accessibility problem could be overcome by increasing the response rate. It was also confirmed that high ratings can be more effectively achieved for high priced hotels by increasing the response rate.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.8
• /
• pp.1164-1173
• /
• 2006

Cellulase from Aspergillus niger, (${\alpha}$-amylase from Bacillus sp. and protease from Bacillus globigii were used as enzyme sources in this study to examine how their respective substrates protect them in two kinds of simulated gastrointestinal tract digesting processes. Avian total digest tract simulation test showed that filter paper, Avicel and cellulose resulted in 7.7, 6.4 and 7.4 times more activity than of unprotected cellulose, respectively. Protease with addition of casein, gelatin or soybean protein showed no significant protection response. Starch protected amylase to be 2.5 times activity of the unprotected one. Monogastric animal total tract digestion simulation test showed that filter paper, Avicel and cellulose resulted in 5.9, 9.0 and 8.8 times activity of unprotected cellulase, respectively. Casein, gelatin and soybean protein resulted in 1.2, 1.3 and 2.0 times activity of unprotected protease, respectively. Starch did not protect amylase activity in monogastric animal total tract simulation. Protection of mixed enzymes by substrates in two animal total tract simulation tests showed that filter paper in combination with soybean protein resulted in 1.5 times activity of unprotected cellulose, but all substrates tested showed no significant protection effect to protease. Soybean protein and starch added at the same time protected the amylase activity to be two times of the unprotected one. Test of non-purified substrate protection in two animal total digest tract simulation showed that cellulase activity increased as BSA (bovine serum albumin) concentration increased, with the highest activity to be 1.3 times of unprotected enzyme. However, BSA showed no significant protection effect to protease. Amylase activity increased to 1.5 times as BSA added more than 1.5% (w/v). Cellulase activity increased to 1.5 times as soybean hull was added higher than 1.5%. Amylase had a significant protection response only when soybean hull added up to 2%. Protease activity was not protected by soybean hull to any significant extent.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.106-106
• /
• 2019

Human needs energy to maintain metabolisms, and these energy sources were uptake foods or nutritions. The most effective source was known for glucose among the nutrients, furthermore the glucose is an important source of energy for blood cells and control brain maintenences cells. But as food is plentiful and eating habits become more westernized, fast food and irregular meal times by works. Nowadays, diabetes were rapidly increased by malnutriton and obesity. Diabetes was the sixth highest on the list of causes of death in Korea, released by the Statistics Korea in 2015, which is considered a serious social problem for adult diseases. Therefore, this study aims to establish the optimal hot water extraction conditions of mixed herbs extract mixture compounds that are effective in diabetes. The independent factors were extraction temperature (X1: $40-120^{\circ}C$), extraction time (X2: 2-10 hrs.), and the ratio of water to sample (X3: 40-200 mg/mL). Their effects were assessed on dependent variables of the extract properties, which included soluble solid contents, Brix of sample extract, total polyphenols content, total flavonoids content and DPPH Radical scavenging activity. As a result, the content of total polyphenol content was the highest in No.12(6 hrs, $120^{\circ}C$, 67 mg/mL) and the highest total flavonoid contents was found in No.16(6 hrs, $80^{\circ}C$, 40 mg/mL). DPPH Radical scavenging activity showed the highest activity in No.7(8 hrs, $100^{\circ}C$, 100 mg/mL).