• Title/Summary/Keyword: 3 stage

Search Result 17,767, Processing Time 0.045 seconds

Induction of Thioredoxin by Oxidative Stress and Overexpression of Thioredoxin in Lung Cancer Tissue (산화 스트레스에 의한 Thioredoxin의 발현과 폐암조직에서의 발현)

  • Lee, Jang-Hoon;Kim, Hyung-Jung;Ahn, Chul-Min;Kim, Sung-Kyu;Lee, Won-Young
    • Tuberculosis and Respiratory Diseases
    • /
    • v.46 no.3
    • /
    • pp.327-337
    • /
    • 1999
  • Background: Reactive oxygen species are involved in multi-stage process of carcinogenesis. The moot of cancer cell lines and cancer cells in tumor tissue produce reactive oxygen species and on the other hand, the activities of catalase, Mn- and CuZn-superoxide dismutase in tumor cells are usually low. These persistent oxidative stress in tumor tissue facilitates tumor invasion and metastasis. 12-kDa thioredoxin, which regulates the intracellular redox potential with glutathione and glutaredoxin is involved in cell activation, proliferation, differentiation and redox-mediated apoptosis. It is also purified as 14-kDa and 10-kDa eooinophilic cytotoxic enhancing factor(ECEF) from human histiocytic cell(U937) and 10-kDa ECEF has more than 20 times eosinophilic stimulation activity than 14-kDa ECEF. It has been reported that adult T-cell leukemia, squamous cell carcinoma of uterine cervix, and hepatocellular carcinoma show increased amounts of human thioredoxin and thioredoxin mRNA is increased in lung cancer. In this study, we investigated the expression of conventional antioxidant enzymes such as catalase, CuZn-SOD, and glutathione peroxidase and thioredoxin in lung cancer tissue compared to adjacent normal lung tissue and the induction of thioredoxin in macrophage cells after treatment of oxidative stress and endotoxin Methods: We measured the amount of conventional antioxidant enzymes such as catalase, CuZn-SOD, and glutathione peroxidase and thioredoxin in lung cancer tissue compared to adjacent normal lung tissue by immunoblot analysis and the induction of thioredoxin in mouse monocyte-macrophage cells(RAW 264.7) by treatment of 5 ${\mu}M$ menadione and 1 ${\mu}g/ml$ endotoxin Results: On immunoblot analysis, the expression of 12-kDa thioredoxin was increased in lung cancer tissue compared to paired normal lung tissue. but the expression of catalase and CuZn-SOD were decreased in lung cancer tissue compared to paired normal tissue and the expression of glutathione peroxidase in lung cancer was variable. The expression of truncated thioredoxin was also increased in lung cancer. When mouse monocyte-macrophage cells were treated with 5 ${\mu}M$ menadione and 1 ${\mu}g/ml$ endotoxin, the expression of thioredoxin was peaked at 12 hrs and sustained to 48 hrs. Conclusion: In contrast with other conventional antioxidants, the expression of 12-kDa and truncated thioredoxin in lung cancer were increased and it is closely associated with persistent oxidative stress in tumor microenvironment. Considering especially the biological functions of truncated thioredoxin, the increased amount of truncated thioredoxin has significant role in tumor growth through cell proliferation.

  • PDF

The Price Dynamics in Futures and Option Markets - based on KOSPI200 stock index market - (주가지수선물가격과 옵션가격의 동적관련성에 관한 연구 - KOSPI 200 주가지수현물시장을 중심으로 -)

  • Seo, Sang-Gu
    • Management & Information Systems Review
    • /
    • v.36 no.3
    • /
    • pp.37-49
    • /
    • 2017
  • This study investigates the dynamic relationship between KOSPI200 stock index and stock index futures and stock index option markets which is its derived from KOSPI200 stock index. We use 5-minutes rate of return data from 2012. 06 to 2014. 12. To empirical analysis, this study use autocorrelation and cross-correlation analysis as a preliminary analysis and then following Stoll and Whaley(1990) and Chan(1992), the multiple regression is estimated to examine the lead-lag patterns between the stock index and stock index futures and option markets by Newey and West's(1987) Empirical results of our study shows as follows. First, there exist a strong autocorrelation in the KOSPI200 stock index before 10minutes but a very weak autocorrelation in the stock index futures and option markets. Second, there is a strong evidence that stock index future and option markets lead KOSPI200 stock index in the cross-correlation analysis. Third, based on the multiple regression, the stock index futures and option markets lead the stock index prior to 10-15 minutes and weak evidence that the stock index leads the future and option markets. This results show that the market efficient of KOSPI200 stock index market is improved as compared to the early stage of stock index future and option market.

  • PDF

Research on Visitor Behavior and Satisfaction with the Nature Trail in Hallasan National Park (한라산국립공원 자연학습탐방로의 이용행태와 이용객만족에 관한 연구)

  • Kim, Jeong-Min
    • Korean Journal of Environment and Ecology
    • /
    • v.21 no.3
    • /
    • pp.223-234
    • /
    • 2007
  • The study, executed with Hallasan National Park, which deserves to be a typical ecotourism destination, aims to provide basic information on park management for early establishment of ecotourism in a national park by assessing its visitors' behavior and satisfaction with a nature trail established as a series of an environmental interpretation program. The questionnaire survey was conducted at Eorimok Square in the weekday and on the weekend for two months of August and September in 2006, and finally 144 valid samples were used for the analysis. As a result of the research, it revealed that the demographic characteristics of the visitors to Hallasan National Park tended to coincide with those of the visitors to other national parks In Korea. On the whole, it showed their low recognition level of nature trails built up in national parks and less experience in using them. However, the visitors' satisfaction level and intention of re-visit, and recommendation to others were comparatively higher after actually using the nature trail at the site of Hallasan National Park, which hints at the possibility of national parks' much weightier role as the ground for ecology education and the functional expansion of the environmental interpretation-related facilities and programs. As for the attributes having effects on users' satisfaction with a nature trail, substantial aspects such as accessibility, safety, uniqueness and interest in environmental interpretation, and educational quality as well as physical facility management were revealed to have equal effects on users' satisfaction level, so there still remain a lot of pending issues over the reality of national parks in the initial stage of ecotourism staying at the level of the introduction and establishment of the facilities for environmental interpretation. This research had surveyed visitors to Hallasan National Park and limited to the nature trail only. For more systematic and practical ecological management of a national park, the in-depth understanding of the attributes affecting satisfaction of ecotourists, including nature trails and other environmental interpretation programs, and more sophisticated measuring tools are needed.

The Key Success Factors of University Entrepreneurship Education: Implication from USA University Cases (대학 창업교육 핵심 성공요인: 미국 대학 사례의 시사점)

  • Choi, Jong-In;Park, Chygwan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.8 no.3
    • /
    • pp.85-96
    • /
    • 2013
  • Entrepreneurship courses and programs in Korean universities tend to increase steadily but seem to have some limitations. They are usually recognized as another domain of Business Administration. Entrepreneurship program is practical like Business Administration but should be much more interdisciplinary than that. Because Korean Entrepreneurship programs are in the early stage, they must be reinforced with factors such as education culture, faculties, curriculum and relationships with communities. This study aims to get some implications from Entrepreneurship programs have been run by universities in America in order to facilitate Entrepreneurship program in Korean universities. Based on 11 success factors found by our case universities' Entrepreneurship programs and Kauffman Campus, this study has drawn implications of critical success factors of Entrepreneurship programs as follow. First of all, because Entrepreneurship programs should focus on Entrepreneurship mind sets such as innovative idea generation and courage to overcome risk, it is more desirable that Entrepreneurship programs are introduced in all departments of universities such as Arts, Science and Engineering. These programs also need to take interdisciplinary approach and required to be opened from liberal arts course. In order to be sustained during all their academic careers, vision, mission and strategy for Entrepreneurship programs should be based on strong leadership and support of top leaders. Entrepreneurship culture of each university is also one of the most important success factors. Entrepreneurship programs not only as major programs but also as specific Entrepreneurship minors designed for departments such as Arts, Science and Engineering could be considered according to each university's situation. This study also suggest to make a motivation system for Entrepreneurship faculties, Ph d. programs for Entrepreneurship, communication network for Entrepreneurship programs and mentor system in community. To begin Entrepreneurship programs, it also needs to develop good education contents as many as possible. When it concerned with teaching method, project based 4 year program can be suggested to be effective and efficient. To introduce project based program that should be consistent till participants' graduation, university must prepare regulations to support team teaching, mentor and interdisciplinary cooperation. To dissipate the concept that Entrepreneurship is another version of management, this study support the idea that Entrepreneurship programs should be designed and run by independent and central-focused governance system, Entrepreneurship education center.

  • PDF

Empirical Research on the R&D Investment and Performance of Venture Businesses (벤처기업의 R&D 투자와 성과에 관한 실증연구)

  • Lee, Dong-Ki;Lee, Cheol-Kyu;Kim, Jung-Hwan
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.3 no.1
    • /
    • pp.1-28
    • /
    • 2008
  • In this research, an empirical analysis was performed to determine the correlation between management performance and Empirical Research on the R&D investment for domestic venture businesses in each industry. Specifically, an empirical analysis for each industry was attempted not only to clarify the general hypothesis on the relationship between management performance and R&D investment for venture businesses but also to demonstrate that differences exist for each industry. Empirical analysis was conducted for eight industries with respect to the $2002{\sim}2006$ panel data extracted as investigative results from the "Investigation Report on Science and Technology R&D Activities" published by the Ministry of Science and Technology. Industrial classification was limited to the middle-level classification (2-digit) in the Korea Standard Industry Code (KSIC) owing to the limited number of panels. Although this research only verified the overall positive effect of R&D activities and funds for existing research on corporate value or productivity and management performance, it was able to document the difference for each individual industry and each business size unlike existing research. Furthermore, the reliability of the research results was enhanced by targeting companies that have been continuously conducting R&D and management activities using consistent 5-year panel data in the analysis. Again, this was something that existing research did not have. Finally, through the use of recent data from 2002 after the IMF economic crisis up to 2006 in the empirical analysis, this research proposed the problems due to the prevailing circumstances at the time of entering the advanced nation stage based on an empirical analysis; the prevailing problems during the pursuit of advanced nation status before the IMF crisis broke out were not tackled. The key empirical analysis yielded several results. First, capital and size of the labor force have a positive correlation with the management performance for the entire company or the venture business. This applies to all eight industries as the subjects of the analysis. Second, although the number of years since a company has been established can have positive or negative correlation with management performance for the entire company or venture business in specific industries, a definite overall trend cannot be identified. Third, R&D investment can be said to have an overall positive effect on corporate management performance. Fourth, the size of the research staff cannot be said to be a factor unilaterally affecting the management performance of the entire company or the venture business. Fifth, the number of years a research institute has been in operation, which was assumed to have a positive effect on the management performance of a company because of the accumulated R&D know-how -- definitely acts as a positive factor contributing to the management performance of a company.

  • PDF

Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2013 (설비공학 분야의 최근 연구 동향 : 2013년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.26 no.12
    • /
    • pp.605-619
    • /
    • 2014
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2013. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and relative parts including orifices, dampers and ducts, fuel cells and power plants, cooling and air-conditioning, heat and mass transfer, two phase flow, and the flow around buildings and structures. Research issues dealing with home appliances, flows around buildings, nuclear power plant, and manufacturing processes are newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for general analytical model for desiccant wheels, the effects of water absorption on the thermal conductivity of insulation materials, thermal properties of Octadecane/xGnP shape-stabilized phase change materials and $CO_2$ and $CO_2$-Hydrate mixture, effect of ground source heat pump system, the heat flux meter location for the performance test of a refrigerator vacuum insulation panel, a parallel flow evaporator for a heat pump dryer, the condensation risk assessment of vacuum multi-layer glass and triple glass, optimization of a forced convection type PCM refrigeration module, surface temperature sensor using fluorescent nanoporous thin film. In the area of pool boiling and condensing heat transfer, researches on ammonia inside horizontal smooth small tube, R1234yf on various enhanced surfaces, HFC32/HFC152a on a plain surface, spray cooling up to critical heat flux on a low-fin enhanced surface were actively carried out. In the area of industrial heat exchangers, researches on a fin tube type adsorber, the mass-transfer kinetics of a fin-tube-type adsorption bed, fin-and-tube heat exchangers having sine wave fins and oval tubes, louvered fin heat exchanger were performed. (3) In the field of refrigeration, studies are categorized into three groups namely refrigeration cycle, refrigerant and modeling and control. In the category of refrigeration cycle, studies were focused on the enhancement or optimization of experimental or commercial systems including a R410a VRF(Various Refrigerant Flow) heat pump, a R134a 2-stage screw heat pump and a R134a double-heat source automotive air-conditioner system. In the category of refrigerant, studies were carried out for the application of alternative refrigerants or refrigeration technologies including $CO_2$ water heaters, a R1234yf automotive air-conditioner, a R436b water cooler and a thermoelectric refrigerator. In the category of modeling and control, theoretical and experimental studies were carried out to predict the performance of various thermal and control systems including the long-term energy analysis of a geo-thermal heat pump system coupled to cast-in-place energy piles, the dynamic simulation of a water heater-coupled hybrid heat pump and the numerical simulation of an integral optimum regulating controller for a system heat pump. (4) In building mechanical system research fields, twenty one studies were conducted to achieve effective design of the mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, and renewable energies in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment is mostly focused on indoor environment and building energy. The main researches of indoor environment are related to infiltration, ventilation, leak flow and airtightness performance in residential building. The subjects of building energy are worked on energy saving, operation method and optimum operation of building energy systems. The remained studies are related to the special facility such as cleanroom, internet data center and biosafety laboratory. water supply and drain system, defining standard input variables of BIM (Building Information Modeling) for facility management system, estimating capability and providing operation guidelines of subway station as shelter for refuge and evaluation of pollutant emissions from furniture-like products.

Recent Progress in Air Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2007 (설비공학 분야의 최근 연구 동향 : 2007년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Shin, Dong-Sin;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.20 no.12
    • /
    • pp.844-861
    • /
    • 2008
  • The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

Development of pallet-scale modified atmosphere packaging for 'Tabor' tomatoes (토마토 'Tabor' 품종의 파렛트 단위 MAP 적용 연구)

  • Park, Jong Woo;Kim, Jinse;Park, Seok Ho;Choi, Dong Soo;Choi, Seung Ryul;Kim, Yong Hoon;Lee, Soo Jang;Park, Chun Wan;Lee, Jung Soo
    • Food Science and Preservation
    • /
    • v.23 no.5
    • /
    • pp.614-622
    • /
    • 2016
  • This study was carried out to investigate the effect of modified-atmosphere packaging (MAP) on the quality change of "Tabor" tomatoes during long-term exportation periods. Hydroponics tomatoes were harvested at the turning stage, sorted, and box packed and then packaged in nylon film with a pallet. The packaged pallet was filled with a gas composition (5% $O_2$, 1% $CO_2$, and 94% $N_2$) and stored at $10^{\circ}C$ for three weeks. The quality changes in weight loss, firmness, color, acidity, soluble solids, and microorganism growth were measured every 7 day interval. During the initial storage, the pallet-scale MAP showed slightly higher weight loss and firmness changes when compared to the conventional pallet. The total color change (${\Delta}E$) during ripening was delayed 10% under MAP storage. Acidity, soluble solids and phenolic compound contents decreased with increases in storage time regardless of the storage method; however, the quality changes of tomatoes were delayed in the MAP pallet. Furthermore, the decay rate of the pallet-scale MAP stored for 14 days was less than that of the conventional pallet, and the number of microorganisms was approximately 30% lower in the pallet-scale MAP, showing a positive effect on marketability. These results suggested that the pallet-scale MAP of tomatoes could ensure higher quality and longer storage periods than conventional pallet storage.

Effects of Temperature on the Oviposition, Feeding and Emergence of the Azuki Bean Weevil (Callosobruchus chinensis L.) in the stored beans (저장두류(貯藏豆類)에 대(對)한 팥바구미의 산란(産卵).섭식(攝食) 및 우화(羽化)에 미치는 온도(溫度)의 영향(影響))

  • Kim, Kyu-Chin;Choi, Hyeon-Soon
    • Korean journal of applied entomology
    • /
    • v.26 no.2 s.71
    • /
    • pp.71-81
    • /
    • 1987
  • This study was conducted to study the effects of temperature on the oviposition, feeding and emergence of the azuki bean weevil(ABW) (Callesobruchus chinensis L.) in the stored beans. And ovipositional preference, hatching and emergence on the preference and non-preference hosts were also investigated. ABW has four generations a year and overwinters as larva stage in the bean grains. Optimum oviposition temperature of the ABW ranges from $25^{\circ}C\;to\;30^{\circ}C$. Oviposition preference in different hosts was in the order of azuki bean, mung bean, soy bean, kidney bean, black-soybean, pea. At $25^{\circ}C$, optimum development temperature emergence of period the ABW averaged 29 days on azuki bean, 31 days on mung bean, 49 days on soy bean, 46 days on black-soybean, 34 days on Pea. Percent hatch in different hosts was in the order of azuki bean, mung bean, soy bean, pea, black-soybean, kidney bean. But percent emergence was in the order of azuki bean, mung bean, pea, black-soybean, kidney bean. Especially, in azuki bean and mung bean, percentage of hatching and emergence was very high. And in soy bean and black-soybean, percentage of hatching was high but emergence was low. The kidney bean was hatching but not emergence at all. The longevity at the different temperatures appeared to be $4{\sim}5$ days at $35^{\circ}C,\;5{\sim}7$ days at $25^{\circ}C{\sim}30^{\circ}C$, $10{\sim}15$ days at $20^{\circ}C\;and\;19{\sim}24$ days at $15^{\circ}C$. Kidney bean of feeding non-preference host oviposited at Seed coat and Endosperm, but no larva developed. And cotyledon and embryo parts were not oviposited at all. The percentage of germination of egg laid bean grain and damaged bean grains was low. Especially, the percentage of germination of damaged bean grains was 0% on azuki bean, 5% on black-soy bean, 7% on Pea.

  • PDF

Myanmar's Macroeconomic changes and its Implications for the Invest of Korean Enterprises (미얀마 통상환경의 변화와 한국기업의 투자 및 진출에 관한 시사점)

  • Jung, Sung-Hoon;Kwon, O-Yoon
    • International Commerce and Information Review
    • /
    • v.13 no.4
    • /
    • pp.177-201
    • /
    • 2011
  • Myanmar had fallen behind other southeast asian nations since Burmese way to Socialism settled down. However, historically second election in Myanmar hold in 2011 and dramatic changes in areas such as Special Economic Zone announcement, the very huge inflows of foreign direct investment in a year of 2009, the infrastructure building projects, a permit of the right to strike for Labour Organization in Myanmar etc. Particularly, Foreign investments and trade with neighbouring countries are actively growing and also with Korea. But investments of Korea in Myanmar relatively are not diversity, with limited sectors such as mining and sewing manufacturing. In this point of view, this paper is trying to make implications for strategies of entry and investments of Korea in Myanmar by using previous papers related to Myanmar economies, trade and foreign investments with updated statistical data. The implications for Korea is that recently Myanmar economy is in its early stages of development. Although it can occur huge demand of railway, road, communications and constructions related to social infrastructures essentially needed for development of a country, these sectors relatively need huge investments. On the other hands, textile and sewing industry relatively need smaller investments in which investors can utilize low labour cost and a position for export to third countries. But those firms which set up for those purpose in Myanmar might have trouble creating domestic markets in future. Moreover, due to demand which occur in the early stage of growth in Myanmar, trade volume tend to increase and trading is also possible to invest but Myanmar still have lots of problems with infrastructure such as road and logistics and we need to make pre-survey for the costs and benefits of our products Finally, Myanmar government is trying to promote and encourage some of industries such as export-oriented industry, import substitution industry and labour-intensive industry. It can also means they will accumulate capital which can be sources for Myanmar economic growth.

  • PDF