• Journal of Ginseng Research
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• v.44 no.1
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• pp.86-95
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• 2020

Background: Ginsenoside Rb1 (Rb1), one of the most abundant protopanaxadiol-type ginsenosides, exerts excellent neuroprotective effects even though it has low intracephalic exposure. Purpose: The present study aimed to elucidate the apparent contradiction between the pharmacokinetics and pharmacodynamics of Rb1 by studying the mechanisms underlying neuroprotective effects of Rb1 based on regulation of microflora. Methods: A pseudo germ-free (PGF) rat model was established, and neuroprotective effects of Rb1 were compared between conventional and PGF rats. The relative abundances of common probiotics were quantified to reveal the authentic probiotics that dominate in the neuroprotection of Rb1. The expressions of the gamma-aminobutyric acid (GABA) receptors, including GABAA receptors (α2, β2, and γ2) and GABAB receptors (1b and 2), in the normal, ischemia/reperfusion (I/R), and I/R+Rb1 rat hippocampus and striatum were assessed to reveal the neuroprotective mechanism of Rb1. Results: The results showed that microbiota plays a key role in neuroprotection of Rb1. The relative abundance of Lactobacillus helveticus (Lac.H) increased 15.26 fold after pretreatment with Rb1. I/R surgery induced effects on infarct size, neurological deficit score, and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) were prevented by colonizing the rat gastrointestinal tract with Lac.H (1 × 10⁹ CFU) by gavage 15 d before I/R surgery. Both Rb1 and Lac.H upregulated expression of GABA receptors in I/R rats. Coadministration of a GABA_A receptor antagonist significantly attenuated neuroprotective effects of Rb1 and Lac.H. Conclusion: In sum, Rb1 exerts neuroprotective effects by regulating Lac.H and GABA receptors rather than through direct distribution to the target sites.

• Molecules and Cells
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• v.37 no.3
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• pp.213-219
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• 2014

MicroRNAs (miRNAs) represent a class of small non-coding regulatory RNAs that play important roles in normal hematopoiesis, including erythropoiesis. Although studies have identified several miRNAs that regulate erythroid commitment and differentiation, we do not understand the mechanism by which the crucial erythroid transcription factors, GATA-1and NF-E2 directly regulate and control differentiation via miRNA pathways. In this study, we identified miR-199b-5p as a key regulator of human erythropoiesis, and its expression was up-regulated during the erythroid differentiation of K562 cells. Furthermore, the increase of miR-199b-5p in erythroid cells occurred in a GATA-1- and NF-E2-dependent manner during erythrocyte maturation. Both GATA-1 and NF-E2 bound upstream of the miR-199b gene locus and activated its transcription. Forced expression of miRNA-199b-5p in K562 cells affected erythroid cell proliferation and maturation. Moreover, we identified c-Kit as a direct target of miR-199b-5p in erythroid cells. Taken together, our results establish a functional link among the erythroid transcription factors GATA-1/NF-E2, miR-199b-5p and c-Kit, and provide new insights into the coupling of transcription and post-transcription regulation in erythroid differentiation.

• Korean Journal of Construction Engineering and Management
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• v.21 no.5
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• pp.29-37
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• 2020

This study analyzed the importance of factors according to the investor's perspective through a survey of residential real estate experts using AHP and fuzzy theory. Analysis results showed that rent, profitability, traffic accessibility, commercial and infrastructure, and financial regulation are important in common. By expert group, financial and credit groups cited profitability, rent, traffic accessibility, supply and tax benefits, construction and development groups cited traffic accessibility, rent, direct access, profitability, commercial area and infrastructure, and appraisal and evaluation groups cited rent, profitability, transportation accessibility, financial regulation and supply as the most important factors. This showed that it had a preference characteristic that was associated with work. In other words, it focuses most on the financial perspective in investment characteristics, and it values convenience such as accessibility to transportation and commercial districts and infrastructure as its location characteristics. In addition, it was found that easing financial regulations in the market is important to expand investment in real estate. This study aims to help the business feasibility analysis of residential property developers and rational decision-making of general investors who are consumers, taking into account the various perspectives of the expert group.

• Toxicological Research
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• v.21 no.2
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• pp.151-160
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• 2005

In order to monitor the histological and general profiles of lung after direct expose of p,p-DDE, 1, 5 and 10 mg/ml of p,p-DDE were sprayed to male ICR mouse, and seven days after exposure, changes of body weight, lung weight, clinical signs, histological profiles of lung and total WBC in blood were investigated with changes of total cell number and their differential count in bronchoalveolar lavage fluid (BALF). In the present study, a significant and dosage-dependent decrease of body weight was detected in p,p-DDE exposed groups and body weight gains during observational periods (7 days) were also significantly and dosage-dependently decreased in p,p-DDE exposed groups compared to that of vehicle control group. In addition general depression signs were detected in all p,p-DDE exposed groups with dosage-dependent manners, and lung weights were also increased in p,p-DDE exposed groups. Congestion, hemorrhage and severe exudate were observed in the lung of p,p-DDE exposed groups with sarcomatous changes and these signs were also showed by dosage-dependent manners. In addition, foreign body pneumonia signs were observed in the lung of p,p-DDE exposed groups in histological levels. The percentage of ALSA (Area of luminal surface of alveoli) was also significantly and dosage-dependently decreased in p,p-DDE exposed groups and total blood WBC and BALF cell numbers were significantly and dosage-dependently increased in p,p­DDE exposed groups compared to that of vehicle control group and increase percentage of neutrophil, eosinophil, and lymphocyte in BALF were monitored in p,p-DDE exposed groups compared to that of vehicle control group. In conclusion, severe allergic response and/or foreign body pneumonitic changes were induced by direct exposure of p,p-DDE containing beverage. So it is considered that strong and powerful regulation was need to control production of residence of environmental pollutant especially to p,p-DDE.

• Journal of the Korea Convergence Society
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• v.11 no.6
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• pp.401-410
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• 2020

The purpose of this study was to investigate predictors and mediating effects of physical activity and nourishment regulation on well-being among young and middle aged patients on DM medication and to compare between those with non-pharmacological treatment and those without. Data were obtained from 2017 community health survey including 1,480 DM patients with oral medication in the age between 20 and 49. Using SPSS 25.0 and AMOS 25.0, path analysis was performed to explore the association between personal factors (socio-economic status, health habit, eating habit and compliance of health examination) and well-being, along with mediating effects of physical activity. Results demonstrated the different mediating role of physical activity. In medication only group, there was no direct effect of physical activity and no indirect effect of personal factors. Direct effect of physical activity and indirect effects of predictors were found in those with non-pharmacological treatment group. When developing strategies to enhance well-being of young and middle aged diabetic patients, proper reflection of their age specific traits and disease management capability are essential.

• Journal of Distribution Science
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• v.12 no.2
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• pp.73-79
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• 2014

Purpose - The Korean government has revised the distribution industry development law to regulate large-scale retailer operations to protecting medium- and small-scale retailers and traditional markets. According to the revised law, large-scale retailers must follow regulations on operating hours and compulsory store closures two days per month. Based on the revised distribution industry development law, most local governments regulate operation hours and they have adopted compulsory closure programs for large-scale retail stores. However, it is argued that fresh food producers suffer from a decrease in sales based on the compulsory closure of stores operated by large-scale retailers. Large-scale retailers reduce their fresh food orders from agricultural and fishery producers because of the compulsory store closures. Fresh food producers also suffer from a decrease in prices because reduced orders lead to a decrease in auction prices based on the availability of excess goods in wholesale markets. This paper investigates the effects of operation regulations for large-scale retailers on agricultural producers by surveying agricultural and fishery producer organizations. Research design, data, methodology - A survey was conducted on 117 producer organizations of fruits and vegetables, cereals, fisheries, and livestock products from September 10 to October 4, 2012. Survey items are annual sales, shares of sales accounted for by large-scale retailers, reduction of orders and prices from large-scale retailers, methods to deal with the sales reduction, unfair trade practices of large-scale retailers, opinion of the large-scale retailer regulations, and so on. The average sales of the sampled producer organizations are 13.7 billion won and the average share of sales accounted for by large-scale retailers is 35.4%. Results - Survey results show that the sample producer organizations' sales decreased 10.1% because of the compulsory closures of stores operated by large-scale retailers. It is estimated that the total sales of producer organizations decreased 371.2 billion won because of the regulations on the operation of large-scale retailers. In addition to the direct effect of a sales decrease due to order reduction, agricultural and fishery producer organizations suffered from the secondary effect of price reduction in wholesale markets. When orders from large-scale retailers decreased, most agricultural and fishery producer organizations shipped redundant products to wholesale markets, decreasing auction prices. It was estimated that the price received decreased 21.9% when sold in other marketing channels. As producer organization sales decreased, it was reported that the labor force employed by producer organizations also decreased by 15.1%. Therefore, we can conclude that the regulations for large-scale retailer operations resulted in negative impacts on agricultural producers. Conclusions - Although the sales reduction due to the regulations for large-scale retailer operations are not great, the cumulative effects due to the continued compulsory closure of stores operated by large-scale retailers could be great. This paper suggests governmental programs that could help agricultural producer organizations to find new and effective marketing channels such as direct marketing, farmers' markets, exports, Internet shopping, and so on.

• KSBB Journal
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• v.27 no.5
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• pp.308-312
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• 2012

Argon-plasma jet (Ar-PJ) is generated by ionizing Ar gas, and the resulting Ar-PJ consists of a mixture of neutral particles, positive ions, negative electrons, and various reactive species. Although Ar-PJ has been used in various biomedical applications, little is known about the biological effects on cells located near the plasma-exposed region. Here, we investigated the effects of the Ar-PJ on actin cytoskeleton of mouse embryonic fibroblasts (MEFs) in response to indirect as well as direct exposure to Ar-PJ. This Ar-PJ was generated at 500 mL/min of flow rate and 100 V electric power by our device mainly consisting of electrodes, dielectrics, and a high-voltage power supply. Because actin cytoskeleton is the key cellular machinery involved in cellular movement and is implicated in regulation of cancer metastasis and thus resulting in a highly desirable cancer therapeutic target, we examined the actin filament architectures in Ar-PJ-treated MEFs by staining with an actin-specific phalloidin labeled with fluorescent dye. Interestingly, the Ar-PJ treatment causes destabilization of actin filament architectures in the regions indirectly exposed to Ar-PJ, but no differences in MEFs treated with Ar gas alone and in untreated cell control, indicating that this phenomenon is a specific cellular response against Ar-PJ in the live cells, which are indirectly exposed to Ar-PJ. Collectively, our study raises the possibility that Ar-PJ may have potential as anti-cancer drug effect through direct destabilization of the actin cytoskeleton.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.1-16
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• 2021

The purpose of this study is to examine how the Korean government has intervened in the venture capital market so far and empirically investigate whether the government's policies on venture capital have stimulated venture capital's early-stage investment. To this end, this study classified the government's market intervention in the venture capital market by stage by studying the related literature and applying and analyzing the case in Korea. And, this study empirically analyzed the effectiveness of the Korean government's policy to revitalize the early-stage investment of venture capital, which is the most important purpose of government intervention. For empirical analysis, yearly data from 2004 to 2018 provided by the Korea Venture Capital Association and Korea Fund of Funds were analyzed using time series statistical analysis and macrodynamics. As a result of the case study, the Korean government has intervened in the venture capital market through direct investment for 25 years, and has been intervening through indirect investment for the next 18 years. As a result of time-series statistical analysis, the government's fiscal investment to increase the formation of venture capital funds and the increase in the ratio of special-purpose funds that mandate a certain percentage of early-stage investment increased the early-stage investment of venture capital. However, macrodynamics showed a trend in the opposite direction from this time series statistical analysis from 2016. In conclusion, this study interprets the trend in the opposite direction to the time series statistical analysis results as the government's erroneous regulation on the venture capital investment method and the recent lack of effectiveness of direct intervention through the government's indirect investment method. In addition, based on the results of case studies and empirical studies, this study made six policy proposals necessary for indirect government intervention.

• International Journal of Vascular Biomedical Engineering
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• v.1 no.2
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• pp.13-19
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• 2003

Endothelial release of nitric oxide (NO) contributes to the regulation of vascular tone by inducing vascular relaxation. To estimate the blood flow-dependent nitric oxide level and half-life (T1/2) of nitric oxide in vivo state, we investigated the change of aortic NO currents during the change of aortic blood flow rate using NO-selective electrode system and electromagnetic flowmeter in the aorta of anesthetized rats. Resting mean aortic blood flow rate was $49.6{\pm}5.6ml/min$ in the anesthetized rats. NO currents in the aorta were increased by the elevation of blood pressure and/or blood flow rate. When the aortic blood flow was occluded by the clamping, aortic NO currents were decreased. The difference of NO concentration between resting state and occluded state was $1.34{\pm}0.26{\mu}M$ (n=7). This NO concentration was estimated as blood flow-dependent nitric oxide concentration in the rats. Also, while the aortic blood flow was occluded, NO currents were decreased with exponential pattern with $12.84{\pm}2.15$ seconds of time constant and $7.70{\pm}1.07$ seconds of half-life. To summarize, this study suggested that blood flow-dependent NO concentration and half-life of nitric oxide were about $1.3{\mu}M$ and 7.7 seconds, respectively, in the aorta of anesthetized rats. The nitric oxide-selective electrode system is useful for the direct and continuous measurement of NO in vivo state.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.13-19
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• 2003

As the environmental pollution becomes serious global problem, the regulation of emission exhausted from automobiles is strengthen. Therefore, it is very important to know how to reduce the NOx and PM simultaneously in diesel engines, which has lot of merits such as high thermal efficiency, low fuel consumption and durability. By this reason, the new concept called as Homogeneous Charge Compression Ignition(HCCI) engines are spotlighted because this concept reduced NOx and P.M. simultaneously. However, it is well known that HCCI engines increased HC and CO. Thus, the investigation of combustion characteristics which consists cool and hot flames for HCCI engines were needed to obtain the optimal combustion condition. In this study, combustion characteristics for direct inject type HCCI engine such as quantity of cool flame and hot flame, ignition timing and ignition delay were investigated to clarify the effects of these parameters on performance. The results revealed that diesel combustion showed the two-stage ignition of cool flame and hot flame, the rate of cool flame increase and hot flame decrease with increasing intake air temperature. On the other hand, the gasoline combustion is the single-stage ignition and ignition timing is near the TDC. In addition mixed fuel combustion showed different phenomenon, which depends on the ratio of gasoline component. Ignition timing of mixed fuel is retarded near the TDC and the ignition delay is increased according to ratio of gasoline.