• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1069-1077
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• 2009

Castration of male pig produces significant negative effects on skeletal muscle development. The androgen receptor (AR), two splice variants of insulin-like growth factor-I (IGF-I Ea and MGF) and the myostatin gene may play important roles in this process. In the present study, the expression of AR, IGF-I Ea, MGF and myostatin genes in three skeletal muscles, the brachialis, longissimus and semitendinosus, were studied using real-time quantitative RT-PCR. Our experimental design used 14 pairs of male Landrace sire${\times}$Yorkshire dam piglets. The two piglets in each pair were full sibs, one of which was castrated at 21 d of age; the other remained intact. The study group was divided into subgroups of equal size. Animals in the first subgroup were slaughtered at 147 d and those of the second at 210 d of age. Carcass weight and lean meat yield were similar between boars and barrows at 147 d of age (p>0.05), whereas barrows had lower carcass weight and less lean meat yield at 210 d of age (p<0.05). Castration caused down-regulation of AR gene expression at both 147 and 210 d of age (p<0.05). The two splice variants of the IGF-I gene from porcine skeletal muscle were cloned using RT-PCR, and it was found that MGF differs from IGF-I Ea in having a 52-base insert in the last coding exon of the mRNA. Both splice variants were down-regulated by castration only at 210 d of age (p<0.05). No differences in expression of the myostatin gene were observed between boars and barrows at either 147 or 210 d of age (p>0.05). These results suggest that the downregulation of AR, IGF-I Ea and MGF gene expression following castration helps to explain the negative effect of castration on skeletal muscle development.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.293-297
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• 1999

The pts operon, which encodes several factors in the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) of Escherichia coli, has multiple promoters which respond to different signals to facilitate quick adaptation to changes in growth conditions. The influence of an 1 kbp DNA region upstream of the pts P0 promoter on pts expression was studied in vitro by employing the DNA templates containing both P0 and P1 promoter with or without the 1 kbp upstream DNA region for in vitro transcription assay. The 1 kbp DNA region upstream of the pts P0 promoter, however, had no effect on pts transcription in vitro. The intracellular concentration of cAMP was measured when cells were grown in the presence of glucose, mannose, or mannitol. The transcription of P0 was increased maximally in the presence of glucose even though the concentration of cAMP in the condition was lowest while the transcription from the P1b was highest when cells were grown in the presence of mannose or mannitol even though the intracellular concentration of cAMP was lower than cells grown in the absence of the sugar. These results suggest the possibility of the existence of a glucose inducible repressor specific for the P0 promoter and a second repressor that is inducible by glucose, mannose and mannitol specific for the P1 promoter.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.565-573
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• 2000

Sewer pipe in Korea is generally constructed with concrete pipes. Moreover, the sewer system is susceptible to the corrosion problem due to the regulation employing anaerobic treatment processes, such as domestic sewage treatment facilities, nightsoil septic tanks and so on. The objective of this study is investigated to experimental test of $H_2S$ production rate affecting corrosion of sewer pipe in Korea. In this study, tube-type and sealed-type reactor were used to examine the reactions in the microorganism suspended growth and biofilm. Furthermore. concentration changes were investigated with COD and sulfate reduction in each reactor. Sulfide production rate was $50.4mg-H_2S/g-VSS{\cdot}d$ in the sealed-type reactor and in the tube-type biofilm reactor was $2.8{\sim}18.8g-H_2S/m^2{\cdot}d$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.551-561
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• 2017

This study attempts to determine the strategy to improve the quality of staff supervision by exploring the experiences of the staff supervision in community welfare centers. For this purpose, multiple case study was performed by conducting in-depth interviews with 10 supervisors for the analysis data and analyzing the resulting themes. The key subjects from their experience were 'Supervisors recognize and prepare the supervision as Challenge and Aspiration', 'Supervision leaves only chaos and frustration', and 'Inspiration from the supervisor and infinite effort result in fruit'. Based on these results, this study suggests the following practical suggestions for the educational, administrative and supportive functions of Supervision. First, educational functions should be proposed as an extension of supervisor's education opportunities and manuals related to educational growth of supervision. Second, the administrative function should be changed to evaluate social welfare institution's evaluation framework so as to evaluate the supervision internal regulation and supervision according to it and various supervision models should be developed. Third, supportive supervision function that can be encouraged for supervisees should be enhanced. This study was meaningful because it presents specific suggestions for supervisors and supervisee's relation and situation in the community welfare center through the qualitative research method.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.446-452
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• 2010

Five year term study from 2002 to 2006 was carried out to examine the effects of continuous long-term application of swine liquid manure on soil chemical properties including heavy metal contents and yield of tomato (Lycopersicon esculentum) and cucumber (Cucumis sativus L.) in a greenhouse. Treatments were conventional chemical fertilizers and three types of swine slurry; Slurry composting and biofiltration (SCB), Thermophilic aerobic oxidation (TAO), and Bio-mineral water (BMW). Total nitrogen level of the SCB, TAO, and BMW was 0.47%, 0.09%, and less than 0.01%, respectively. The heavy metal contents of the three liquid manures were much lower than the Korean regulation level. The soil phosphorus, potassium, and heavy metal contents after five year continuous application of swine slurry were not significantly higher than those of chemical fertilizer use. Contents of heavy metals in leaves of the crops did not show significant difference among treatments. The levels of copper and zinc, plant essential elements, in leaves were in the range of optimum plant growth. Yields of tomato and cucumber for swine liquid manures were not significantly different from that of chemical fertilizer. The results implied that the three types of swine slurry may not deteriorate soil chemical properties including phosphate and trace elements in greenhouse soils when they are applied as a basal fertilization at a recommended nitrogen rate based on soil testing.

• Journal of Technology Innovation
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• v.17 no.1
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• pp.119-148
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• 2009

The paper presents and empirically tests a model of the digital contents(DC) innovation systems that enables us to study interactions between users, service providers, contents developers and network providers, and to examine the relationship between manufacturing innovation and service innovation as well as patterns of innovation in the DC industry. The framework of Gallouj and Weinstein(1997) and Gallouj(2002) is modified into the DC innovation model according to characteristics of the DC industry, that is, user involvement and network externalities. The model is applied to a case analysis that traces the growth of the online game industry in Korea since its introduction. The model offers several advantages over other approaches in understanding the dynamics in the DC industry. Most importantly, it provides a single unified basis within which both service innovation resulting from users and service providers and manufacturing innovation induced by contents developers, platform holders and network providers are analyzed. The distinction between service and manufacturing innovation is important in many ways, for instance in selecting proper government policy tools for promotion or regulation of the DC industry. Second, the Korean online game industry has experienced both radical innovation during the beginning period and non-radical innovation throughout the maturation period. The model developed herein helps to illustrate several types of non-radical innovations such as recombinative innovation that are crucial to sustainable development of the DC industry. Third, the model clarifies impacts of network externalities that are characteristics of the DC industry.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.83-94
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• 2020

Busan Metropolitan City, a research site of this study, was promoted to a metropolitan city in 1995 with the implementation of the local autonomy system, and the overall change was made as it absorbed the surrounding areas to address the shortage of population and space. Twenty-five years after the introduction of the local autonomy system, it is necessary to diagnose whether balanced development of the entire city is being made in accordance with the reorganization of the metropolitan city in terms of spatial structure. In this study, changes in spatial structure and regional characteristics were analyzed by applying population potential, which means potential for future spatial interaction, in time and space. According to the analysis, the development was taking place around the center area and the sub-center established by the urban master plan, but Gangseo-gu and Gijang-gun, which were incorporated in the past, remained stagnant. In addition, it was shown that the spatial expansion of the city was suppressed by the green belt surrounding the city. However, in other regions where the green belt is located, the city has been expanded, which is different from Gijang-gun or Gangseo-gu, which was incorporated into the metropolitan city. Therefore, the cause of the decline in incorporated areas should not be limited to the institutional dimension of land use regulation. Growth management and balanced development plans will be necessary for the development of declining old downtowns and underdeveloped incorporated areas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.1-6
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• 2004

$\beta$-Sitosterol is the major phytosterol in higher plants, including fruits and vegetables. The molecule has been shown to have the potential for prevention and therapy for human cancer. We investigated the effects of $\beta$-sitosterol on the cell proliferation of HCT116 human colon cancer cells in order to understand its anti-proliferative mechanism. $\beta$-Sitosterol treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner. The anti-proliferative effect of HCT116 cells by $\beta$-sitosterol was associated with formation of apoptotic bodies and degradation of $\beta$-catenin protein. In addition, $\beta$-sitosterol-treatment induced a marked accumulation of tumor suppressor p53 and a concomitant induction of cyclin-dependent kinase (Cdk) inhibitor p21 without alteration in the levels of cyclins and Cdks. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of $\beta$-sitosterol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.137-142
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• 2016

We investigated the anti-proliferative effects of solar salt and purified salt (PS) on HepG2 human hepatocellular cancer cells as well as their effects on mRNA and protein expression of apoptosis- and cell cycle-related genes, including Bcl-2, Bax, p53, and p21. Each salt sample suppressed cancer cell proliferation when treated at a concentration of 0.5% or 1%. Especially solar salt from T salt field (SS-T) and solar salt from Y salt field (SS-Y) significantly suppressed proliferation of cancer cells in comparison with PS. Treatment of HepG2 cells with salt samples at a concentration of 1% suppressed expression of Bcl-2 and promoted expression of Bax, p53, and p21 at the mRNA and protein levels in comparison with the control group. Inductively coupled plasma optical emission spectrometry (ICP-OES) showed that SS-T and SS-Y had higher concentrations of Ca, Mg, S, and K than PS, and SS-T contained higher concentrations of these minerals than SS-Y. It seems that Na and mineral contents in solar salt may contribute to regulation of the genes. Taken together, salt, especially mineral rich solar salt, inhibits cancer cell growth by regulating apoptosis and cell cycle-related genes.

• Journal of Acupuncture Research
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• v.32 no.4
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• pp.91-102
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• 2015

Objectives : The Oriental medical device industry is expected to continue to experience significant growth. It should increase its global market share rather than focusing on the domestic market. Countries around the world self-regulate their domestic market, so this study aims to aid in the development of a particular overseas market by introducing the U.S.(the largest market) medical device registration and approval process. Methods : For an understanding of the US medical device licensing process, we researched the relevant regulatory organization (FDA), the history, definition and classification of medical devices, the approval and 510(k) submission process related to substantial equivalence, IEC 60601-1 Edition 3, usability tests, and so on. Results : Medical devices in the United States are assigned to one of three regulatory classes: Class I, Class II and Class III, based on the level of control necessary to assure the safety and effectiveness of the device. If a company's device is classified as Class II and if it is not exempt, a 510k will be required for marketing. 1) A 510(k) is a premarket submission made to the FDA to demonstrate that the new device to be marketed is "substantially equivalent" to a legally marketed device (predicate device) 2) The IEC 60601-1 Edition 3 preparation process, which contains information related to usability, is expensive and time-consuming but a critical requirement. Conclusions : Although the U.S. market has high barriers to entry, access to this, large overseas market will encourage development of the Oriental medical device industry and commercial value enhancement is expected.