• Title/Summary/Keyword: Limiting factors

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Heme Oxygenase-1 as a Potential Therapeutic Target for Hepatoprotection

  • Farombi, Ebenezer Olatunde;Surh, Young-Joon
    • BMB Reports
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    • v.39 no.5
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    • pp.479-491
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    • 2006
  • Heme oxygenase (HO), the rate limiting enzyme in the breakdown of heme into carbon monoxide (CO), iron and bilirubin, has recently received overwhelming research attention. To date three mammalian HO isozymes have been identified, and the only inducible form is HO-1 while HO-2 and HO-3 are constitutively expressed. Advances in unveiling signal transduction network indicate that a battery of redox-sensitive transcription factors, such as activator protein-1 (AP-1), nuclear factor-kappa B (NF-${\kappa}B$) and nuclear factor E2-related factor-2 (Nrf2), and their upstream kinases including mitogen-activated protein kinases play an important regulatory role in HO-1 gene induction. The products of the HO-catalyzed reaction, particularly CO and biliverdin/bilirubin have been shown to exert protective effects in several organs against oxidative and other noxious stimuli. In this context, it is interesting to note that induction of HO-1 expression contributes to protection against liver damage induced by several chemical compounds such as acetaminophen, carbon tetrachloride and heavy metals, suggesting HO-1 induction as an important cellular endeavor for hepatoprotection. The focus of this review is on the significance of targeted induction of HO-1 as a potential therapeutic strategy to protect against chemically-induced liver injury as well as hepatocarcinogenesis.

Assessments of utilization and Management Practices of Frozen Convenience Foods in Elementary School Foodservice Operations in Inchon (인천지역 초등학교 급식의 냉동가공식품 이용률 및 관리실태)

  • Park, Gyeong-Suk;Choe, Eun-Hui;Ryu, Gyeong
    • Journal of the Korean Dietetic Association
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    • v.10 no.2
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    • pp.246-257
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    • 2004
  • To provide basic information for the proper usage of frozen convenience foods in elementary school foodservice operations, 51 dietitian employeed in school foodservices in Inchon were surveyed. Among the frozen convenience foods, dumpling-type foods(60.8%) and processed meats(40.4%)were used widely in school foodservice. Generally, the frequency of using frozen food items was fewer than 1 time per month. More than 15% of respondents were using pork cutlet, chicken, chickenball, dumpling stuffed with meat about 2-3 times per month. Sweet and sour pork(Tangsuyuk), kebap(Sanjuk), fish/shrimp cutlet, fried potato items were used only fewer than 1 time per month. Dietitian's age, carrier, employed status influenced the utilization rate. The grand mean of satisfaction score was 3.36 out of 5. The factors affecting satisfaction in using frozen foods were sanitation, taste, price, nutrition, food additives in order. The major reasons of utilizaing frozen convenience foods were 'improved labor productivity(4.47)' and 'meet customer preference(4.25)'. The limiting factors in using frozen foods were taste(35.3%), price(23.5%), nutrition(17.6%). The management practices of frozen convenience foods through food processing flow were assessed. Average performance rate was 64.7%. To enlarge the usage of frozen convenience foods in foodservice operations, dietitians should observe sanitary practices.

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Long-term Variations of Phytoplankton Community in Coastal Waters of Kyoungju City Area (경주시 연안해역의 식물플랑크톤 군집 장기 변동)

  • KIM, Hyun-Jung;PARK, Jae Yeong;SON, Min Ho;MOON, Chang-Ho
    • Journal of Fisheries and Marine Sciences Education
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    • v.28 no.5
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    • pp.1417-1434
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    • 2016
  • Starting from the February 2008 till the end of November 2014, abundance of phytoplankton and their composition living in the coastal waters of Kyoungju city were investigated. Environmental and biological properties were also observed at 10 different stations on a seasonal basis. Due to the environmental variables, fluctuating pattern was appeared during the entire period of observation with different degree, as compared to those found in other costal waters in the East Sea. The concentration of phosphate was turned out to be very low which was even less than threshold level in the study area. Phytoplankton community structure was dominated by diatoms (both micro- and nanoplankton fractions) for several years and seasonal succession was also relied on the diatoms. The importance of dinoflagellates in the community was relatively low. Abundance of phytoplankton was heavily affected by physical factors in the surface water, however, affected more by chemical factors including nutrients in the deep water. For periods of this study, the phosphate concentrations was observed in an extremely low, which indicates that the main limiting factor affecting phytoplankton growth could be phosphate.

Brachytherapy in Coronary Artery Disease (관상동맥질환의 방사성동위원소 치료)

  • Song, Ho-Chun
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.2
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    • pp.113-119
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    • 2006
  • Coronary artery disease is a loading cause of morbidity and mortality across the world. Percutaneous coronary intervention has become the major technique of revascularization. However, restenosis remains a major limitation of this procedure. Recently the need for repeat intervention due to restenosis, the most vexing long-term failure of percutaneous coronary intervention, has been significantly reduced owing to the introduction of two major advances, intracoronary brachytherapy and the drug-eluting stents. Intracoronary brachytherapy has been employed in recent years to prevent restenosis lesions with effective results, principally in in-stent restenosis. Restenosis is generally considered as au excessive form of normal wound healing divided up in precesses: elastic recoil, neointimal hyperplasia, and negative vascular remodeling. Restenosis has previously been regarded as a proliferative process in which neointimal thickening, mediated by a cascade of inflammatory mediators and other factors, is the key factor. Ionizing radiation has been shown to decrease the proliferative response to injury in animal models of restenosis. Subsequently, several randomized, double blind trials have demonstrated that intracoronary brachytherapy can reduce the rates of both angiographic restenosis and clinical event rates in patients undergoing percutaneous coronary intervention for in stent restenosis. Some problems, such as late thrombosis and edge restenosis, have been identified as limiting factors of this technique. Brachytherapy is a promising method of preventing and treating coronary artery restenosis.

Soybean Improvement for Drought, Salt and Flooding Tolerance

  • Pathan, Safiullah;Nguyen, Henry T.;Sharp, Robert E.;Shannon, J. Grover
    • Korean Journal of Breeding Science
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    • v.42 no.4
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    • pp.329-338
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    • 2010
  • Drought, salinity and flooding are three important abiotic factors limiting soybean production worldwide. Irrigation, soil reclamation, and drainage systems are not generally available or economically feasible for soybean production. Therefore, productive soybean varieties with tolerance are a cost effective means for reducing yield losses due to these factors. Genetic variability for higher tolerance to drought, salt and flooding is important. However, only a small portion of nearly 200,000 world soybean accessions have been screened to find genotypes with tolerance for use in breeding programs. Evaluation for tolerance to drought, salinity and flooding is difficult due to lack of faster, cost effective, repeatable screening methods. Soybean strains with higher tolerance to the above stresses have been identified. Crosses with lines with drought, salt and flooding tolerance through conventional breeding has made a significant contribution to improving tolerance to abiotic stress in soybean. Molecular markers associated with tolerance to drought, salt and flooding will allow faster, reliable screening for these traits. Germplasm resources, genome sequence information and various genomic tools are available for soybean. Integration of genomic tools coupled with well-designed breeding strategies and effective uses of these resources will help to develop soybean varieties with higher tolerance to drought, salt and flooding.

Analysis of the competition between SSM's and Small and Medium sized Distributor on System Thinking (시스템사고로 분석한 SSM과 중소유통사업자 경쟁관계 분석)

  • Jung, Jaerim
    • Journal of Industrial Convergence
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    • v.15 no.2
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    • pp.37-43
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    • 2017
  • As the number of SSM(Super Supermarket) has been growing, the conflict between large companies and small-to-medium retailers is being deeper in which large-sized market has been growing rapidly and small to medium retailers has been depressed. To solve the conflict, the government enacted the system of business limiting of large enterprises by SMEs. It brought growth of sales of small-to-medium retailers. However, unintended effects were caused by the system. This research aims to analyze underlying structure beyond conflicts between SSM and small to medium retailers using system thinking and draw relationships between key factors. Thus we can provide political alternatives through simulation model which is developed based on the factors.

The impacts of exercise on pediatric obesity

  • Headid, Ronald J. III;Park, Song-Young
    • Clinical and Experimental Pediatrics
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    • v.64 no.5
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    • pp.196-207
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    • 2021
  • Over the last few decades, the rates of pediatric obesity have more than doubled regardless of sociodemographic categorization, and despite these rates plateauing in recent years there continues to be an increase in the severity of obesity in children and adolescents. This review will discuss the pediatric obesity mediated cardiovascular disease (CVD) risk factors such as attenuated levels of satiety and energy metabolism hormones, insulin resistance, vascular endothelial dysfunction, and arterial stiffness. Additionally, early intervention to combat pediatric obesity is critical as obesity has been suggested to track into adulthood, and these obese children and adolescents are at an increased risk of early mortality. Current suggested strategies to combat pediatric obesity are modifying diet, limiting sedentary behavior, and increasing physical activity. The effects of exercise intervention on metabolic hormones such as leptin and adiponectin, insulin sensitivity/resistance, and body fat in obese children and adolescents will be discussed along with the exercise modality, intensity, and duration. Specifically, this review will focus on the differential effects of aerobic exercise, resistance training, and combined exercise on the cardiovascular risks in pediatric obesity. This review outlines the evidence that exercise intervention is a beneficial therapeutic strategy to reduce the risk factors for CVD and the ideal exercise prescription to combat pediatric obesity should contain both muscle strengthening and aerobic components with an emphasis on fat mass reduction and long-term adherence.

Analysis of Digitalization Strategies for Tourism Industry in South Korea

  • Ji Young JEONG;Mamurbek KARIMOV;Mamta BHATT;Ji Young HAN;Yong Geun KIM
    • The Journal of Economics, Marketing and Management
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    • v.12 no.1
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    • pp.17-28
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    • 2024
  • Purpose: This paper is designed to deliver a deeper understanding of the implications of digitalization strategies in the tourism industry, exploring the opportunities and challenges in South Korea. Research design, data and methodology: To identify effective strategies, an integrated approach is employed in the research that encompasses the Glocal RPM analysis and SANEL HERMES model, as well as the examination of digital tourism factors within the DIANA economy. The data used for this study were derived from multiple sources, including literature review, participation interview, tourist survey and expert questionnaire. By conducting a tourist survey using questionnaires in this research, Glocal RPM and SANEL HERMES hybrid method is used identifying and classifying influencing factors limiting digitalization in tourism. As a final step, experts use a Quantitative Strategic Planning Matrix to propose, assess, and rank a number of digitalization strategies. Results: According to the analysis, the study revealed that combining both tools contributes to a more holistic understanding of the environment, uncovering the positives and negatives from diverse perspectives. The average satisfaction percentage of experts was determined to be 38%, indicating anatal level of digitalization for tourism industry in South Korea. Conclusions: These results can serve as a valuable guide for policymakers and stakeholders in formulating targeted strategies to enhance glocalization, rationality, professionalism, and morality within the digitalization context.

Electron-microscopic studies on fine structure and enzyme activity in the axenic and conventional strains of Entamoeba histolytica (이질아메바(Entamoeba histolytica)의 미세구조 및 효소활성에 관한 전자현미경적 연구)

  • Yong, Tae-Sun;Jeong, Pyeong-Rim;Lee, Geun-Tae
    • Parasites, Hosts and Diseases
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    • v.23 no.2
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    • pp.269-284
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    • 1985
  • The metabolism of Entamoeba histolytica would be affected by various environmental factors, and alteration of the environment was known to afEect the fine structure of 5. histolytica. The present study was designed electronmicroscopically to investigate the ultrastructure and enzyme activities in the aEonic and conventional strains of 5. histolytica. The trophozoites of axenically cultivated HK-9 strain and conventional YS-27 and YS-49 strains of 5. histolytica were collected and liKed with 4% paraformaldehyde/0.1M cacodylate buffier(pH 74), After washing them by centrifugation, 1% warm agar was added in the sediment. Solidified agar with the trophozoites was cut into $lmm^3$ cubes, and incubated in the various substrates to observe enzyme activities. Then, the specimen was post-fixed with 3% glutaraldehyde/0.1M cacodylate buffer (PH 7.4) and 1% osmium tetroBide/0.1M cacodylate buffier (pH 7.4) , dehydrated in ascending ethanol series and embedded in epoxy resin. These were sectioned on an ultramicrotome and observed with a transmission electronmicroscope. The procedures for the observation of the fine structure were same as the above, except for the incubation in the substrate. The sections were stained with uranyl acetate and lead citrate. For the observation of the surface of the amoebae, scanning-electronmicroscopy was carried out. The results obtained in the present study are summarized as follows: 1. The fuzzy coat around double-layered plasma membrane of 5. histolytica was more irregularly and densely distributed in the conventional strains (YS-27, YS-49 strains) than in the axonic strain (HK-9 strain). 2. The endosomes, button bodies and chromatin material were surrounded by a double-layered nuclear membrane having scattered nuclear fores. The paranuclear body, mono- or double-layered vacuoles, vacuolar membrane whorls, rosette-like cylindrical bodies, aggregation of cylindrical bodies and helical bodies were found in the cytoplasm of the amoebae. Helical bodies and glycogen granules were generally abundant, while a few smooth endoplasmic reticula were observed in the cytoplasm. 3. Alkaline phosphatase activity was mainly demonstrated in the plasma membrane, limiting membranes of vacuoles and smooth endoplasmic reticula. ATPase activity was observed in the nucleus, limiting membranes of vacuoles and vacuolar membrane whorls. 4. Acid phosphatase activity was commonly demonstrated in the limiting membranes an contents of vacuoles, Iysosome-like organelles, plasma membrane and the button bodies in the nucleus. The activity was more weakly demonstrated in the HK-9 strain than in the other conventional strains of 5. histolytica. No peroBidase activity was observed in the amoeba strains employed in the present study. 5. With a scanning electron-microscope, no distinct structural differences were observed between the amoeba strains. All the trophozoite forms of the amoebae showed crater-like depressions and rugged features on the outer surface.

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Study on Rate-Limiting Factors with a Heavy Loaded Biofilter

  • Son, Hyun-Keun
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.E2
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    • pp.74-81
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    • 2007
  • Feasibility test for a biofilter was performed to treat VOCs. The applied loading rate to the biofilter was calculated between 60 to $3,700\;kg\;COD/m^3$. Trimethyl-pentene and trimethyl-hexene were the two most dominant compounds and they occupy about 85 percent. During the acclimation period, it is desirable for a biofilter to receive relatively lower VOCs concentration and flow rate, until it can adjust to new substrate and operational environment. Temperature at various points inside the biofilter reactor was observed with more than 23 temperature sensors. With steam heating, temperatures of the top sections of the media were greater than those of bottom sections. Without steam heating, intermediate stages generally had higher temperature measurement than those of bottom and top stages. Because the pH values for different biofilter materials vary significantly, measurement of the pH for the mixture of different combinations of biofilter materials is necessary. Based on the types and brands of media, the measured pH ranged from 5.38 to 9.10. The range of measured pH of different mixtures with perlite, compost, saw dust, peat moss, limestone, vermiculite was 7.05 to 8.62.