• Title/Summary/Keyword: research activities

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Antioxidant Activities of Decursinol Angelate and Decursin from Angelica gigas Roots

  • Lee, Sang-Hyun;Lee, Yeon-Sil;Jung, Sang-Hoon;Shin, Kuk-Hyun;Kim, Bak-Kwang;Kang, Sam-Sik
    • Natural Product Sciences
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    • v.9 no.3
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    • pp.170-173
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    • 2003
  • The anti-oxidant activities of decursinol angelate (1) and decursin (2) isolated from Angelica gigas were investigated. These two coumarins exhibited decrease in serum transaminase activities elevated by hepatic damage induced by $CCl_4-intoxication$ in rats. They also showed increase in anti-oxidant enzyme such as hepatic cytosolic superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-px) in $CCl_4-intoxicated$ rats. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas possess not only the anti-oxidant, but also the hepatoprotective activities in rats.

Immune Stimulating Efficacy of Soluble β-1,3-glucans (수용성 β-1,3-glucans의 면역 활성 효능에 대한 연구)

  • Shim, Jung-Hyun;Choi, Won-A;Kim, Jong-Wan;Lee, Hae-Sook;Baek, Tae-Woong;Cho, Min-Cheol;Lee, Kyung-Ae;Sang, Byung-Chan;Yoon, Do-Young
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.156-163
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    • 2003
  • Background: $\beta$-1,3-glucans are well known to enhance the immune reactions, resulting in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. $\beta$-1, 3-glucans have various activities depending on molecular weight, degree of branching, conformation, water-solubility and intermolecular association. However, the $\beta$-1,3-glucan linked backbone structure is essential and $\beta$-D-glucopyranosyl units are required for immuno-potentiating activities. Result: In this study, we tested the immunophamacological activities of soluble $\beta$-1,3-glucans and confirmed the following activities: (1) $IFN-{\gamma}$ production in PBMCs in the presence or the absence of PHA, LPS, or IL-18; (2) induction of various cytokines in the spleen and thymus; (3) adjuvant effect on the antibody production; (4) nitrogen oxide synthesis in macrophages; (5) the cytotoxic and antitumor effects on cell lines and ICR mice. Conclusion: These results strongly suggested that $\beta$-1,3-glucans possessed various immuno-pharmacological activities.

Plants with Liver Protective Activities (III) (강간제(强肝劑)로 사용된 생약(生藥)의 조사(調査) 연구(硏究) (III))

  • Chang, Il-Moo;YunChoi, Hye-Sook
    • Korean Journal of Pharmacognosy
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    • v.10 no.2
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    • pp.79-82
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    • 1979
  • Total fourty-four medicinal plants described in old literatures to be hepatotonic were evaluated their potential hepatotonic activities against an animal model of hepatitis. Tweenty-seven plants extracts appeared to be significant hepatotonic activities, whereas twelve plants extracts exhibited rather some toxicity. And five plants extracts showed no significant hapatotonic activities and toxicity.

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The Chemistry of Secondary Products from Acanthopanax Species and their Pharmacological Activities

  • Shin, Kuk-Hyun;Lee, Sang-Hyun
    • Natural Product Sciences
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    • v.8 no.4
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    • pp.111-126
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    • 2002
  • The chemistry of secondary products from Acanthopanax species and their pharmacological activities were reviewed. A nitrogenous compound, a furan compound, a quinoid, benzoids, coumarins, phenylpropanoids, lignans, flavonoids, terpenoids, phytosterols, polyacetylenes, a pyrimidine, cyclitols, monosaccharides and an aliphatic alcohol have been isolated from Acanthopanax species and have been shown to have various levels of activities such as anti-bacterial, anti-cancer, anti-gout, anti-hepatitis, anti-hyperglycemic, anti-inflammatory, anti-leishmanicidic, anti-oxidant, anti-pyretic, anti-xanthine oxidase, choleretic, hemostatic, hypocholesterolemic, immunostimulatory and radioprotectant effects, etc.

A Suggestion on the Promotive Directions of Quality Circle Activity (품질분임조 활동의 진흥방향 제안에 관한 연구)

  • Lee, Kang-In;Kim, Hyun
    • Journal of Korean Society for Quality Management
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    • v.35 no.2
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    • pp.1-26
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    • 2007
  • The purpose of this research is to suggest the promotive directions of Quality Circle activity. Since 1975, variety of organizations in Korea have widely the implemented Quality Circle activities for their management systems. Today, Companies are facing the harsh realities of a competitive environment. This is no time for revolutionary change. Instead, Companies are instituting revolutionary change meant to have impact within a very short time frame. The Worker's Quality Circle activity is, essentially, a trouble shooting oriented voluntary small group within their working place to improve the surroundings creatively. The industries have enthusiastically used Quality Circle activities and were influenced from them. The Quality Circle activities can be regarded as a kind of Knowledge Management where new knowledge is created and knowledge is shared in the economy. However, the academics were less interested in this subject, as a result, there were no systematic guidances for Quality Circle activities. Also, the government was less interested in these activities, as a result, there were no systematic policy making for Quality Circle activities. Thus, in this research, the promotive directions for Quality Circle activities were suggested which were based on the results of survey Questionnaires presented to promoters of the domestic companies. As a results of this research, to maximize the effect of TQM(Total Quality Management) in the nationwide, Quality Circle activity as a bottom-up management should be more expanded and revitalized.

Government R&D Programs and Innovation Activities (정부 기술개발 지원사업이 중소기업의 혁신활동에 미치는 영향)

  • Lee, Byungheon;Park, Sangmoon
    • Asia-Pacific Journal of Business
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    • v.11 no.4
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    • pp.177-188
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    • 2020
  • Purpose - The purpose of this study was to examine the effect of government R&D programs on firm innovation activities. Design/methodology/approach - This study analyzed survey data on innovation survey in Korea. To investigate our research hypothesis we used ordered logit regression analysis. Findings - This study unveils different effects of diverse government R&D programs on firm innovation activities. Most of government programs-R&D tax incentives, information/training, and marketing supports-have positive effects on management innovation activities and negative effects of the usage of procurement programs on management innovation efforts. Some government programs-R&D tax incentives, R&D grants, information/training-have positive effects on technological innovation activities. Research implications or Originality - This paper investigates the effects of diverse government R&D programs on technological and management innovation activities. We examine simultaneous effects of multiple government R&D programs rather than effects of independent R&D programs. This result can contribute to develop more effective government R&D programs to support firm innovation activities.

Product Quality Control Activities and Repurchase Intention in Agro-product E-commerce

  • Zi-Hui BAI;Chao XU;Sung Eui CHO
    • The Journal of Economics, Marketing and Management
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    • v.12 no.1
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    • pp.1-15
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    • 2024
  • Purpose: This study aims to explore the critical factors in the quality control activities of agricultural products in e-commerce companies and analyze how these factors affect customers' perceived value and repurchase intention. Finally, it further reveals the mediating role of perceived value between the factors of quality control activities of agricultural products and customer repurchase intention. Research design, data and methodology: This study identified six independent factors within agricultural product quality control activities: freshness, assurance, diversity, grading, packaging, and timeliness. Subsequently, the impact of these factors on customer repurchase intention was analyzed. Additionally, perceived value was considered as an intermediary variable between the independent and dependent variables. Data was gathered from 269 Chinese consumers who had experience purchasing on agricultural product e-commerce websites. Results: The study results indicate that the relevant factors within agricultural product quality control activities strongly influence customer repurchase intention, with perceived value mediating this relationship. Conclusions: The significance of this study lies in its exploration of the relevant factors within agricultural product e-commerce's product quality control activities. It identifies their impact on customer repurchase intention and confirms the mediating role of perceived value. The results of this research offer valuable insights and practical guidance for academics in related research fields and practitioners in the agricultural product e-commerce industry.

In Vitro and Intracellular Antioxidant Activities of Brown Alga Eisenia bicyclis

  • Yoon, Na-Young;Lee, Sang-Hoon;Wijesekara, Isuru;Kim, Se-Kwon
    • Fisheries and Aquatic Sciences
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    • v.14 no.3
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    • pp.179-185
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    • 2011
  • The antioxidant activities of a methanolic extract of Eisenia bicyclis and its organic solvent fractions, including dichloromethane ($CH_2Cl_2$), ethyl acetate (EtOAc), n-butanol (n-BuOH), and water ($H_2O$) fractions, were investigated. Scavenging activities against DPPH, hydroxyl, superoxide anion, and peroxynitrite radicals were evaluated using electron spin resonance spectrometry; intracellular reactive oxygen species (ROS) were evaluated by a 2',7'-dichlorofluorescein diacetate assay using RAW264.7 mouse macrophages. The antioxidant activities of the individual fractions were: EtOAc>n-BuOH>$CH_2Cl_2$ >$H_2O$. The EtOAc fraction exhibited strong radical scavenging activity and a significantly reduced ROS level in RAW264.7 cells. Moreover, the phenolic contents of the extract and fractions followed the same order as their radical scavenging activities. Our results indicate that E. bicyclis is a valuable natural source of antioxidants that may be applicable to the functional food industry.

A Robust and Device-Free Daily Activities Recognition System using Wi-Fi Signals

  • Ding, Enjie;Zhang, Yue;Xin, Yun;Zhang, Lei;Huo, Yu;Liu, Yafeng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.6
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    • pp.2377-2397
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    • 2020
  • Human activity recognition is widely used in smart homes, health care and indoor monitor. Traditional approaches all need hardware installation or wearable sensors, which incurs additional costs and imposes many restrictions on usage. Therefore, this paper presents a novel device-free activities recognition system based on the advanced wireless technologies. The fine-grained information channel state information (CSI) in the wireless channel is employed as the indicator of human activities. To improve accuracy, both amplitude and phase information of CSI are extracted and shaped into feature vectors for activities recognition. In addition, we discuss the classification accuracy of different features and select the most stable features for feature matrix. Our experimental evaluation in two laboratories of different size demonstrates that the proposed scheme can achieve an average accuracy over 95% and 90% in different scenarios.

Characterization of Human Foamy Virus Integrase Mutant (인간 포미바이러스 인테그라제 돌연변이의 특성)

  • Kang Seung Yi;Oh Soo A;Lee Hak Sung;Han Sung Tai;Shin Cha-Gyun
    • YAKHAK HOEJI
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    • v.49 no.3
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    • pp.198-204
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    • 2005
  • Human foamy virus (HFV) integrase mediates integration of viral c-DNA into cellular DNA. In this process, HFV integrase recognizes its own viral DNA specifically and catalyzes insertion of viral c-DNA. In order to study catalytic domains and residues, three deletion mutants and two point mutants of HFV integrase were constructed and analyzed with respect to enzymatic activities. The C-terminal deletion mutant showed decreased enzymatic activities while the N-terminal deletion mutant lost the activities completely, indicating that the N-terminal domain is more important than the C-terminal domain in enzymatic reaction. The point mutants, in which an aspartic acid at the 164th position or a glutamic acid at the 200th position of the HFV integrase protein was changed to an alanine, lost the enzymatic activities completely. However, they were well complemented with other defective deletion mutants to recover enzymatic activities partially. Therefore, these results suggest that the aspartic acid and glutamic acid at the respective 164th and 200th positions are catalytic residues for enzymatic reaction.