• KIEE International Transaction on Systems and Control
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• v.2D no.2
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• pp.78-91
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• 2002

In the thermal power plant, there are six manipulated variables: main steam flow, feedwater flow, fuel flow, air flow, spray flow, and gas recirculation flow. There are five controlled variables: generator output, main steam pressure, main steam temperature, exhaust gas density, and reheater steam temperature. Therefore, the thermal power plant control system is a multinput and output system. In the control system, the main steam temperature is typically regulated by the fuel flow rate and the spray flow rate, and the reheater steam temperature is regulated by the gas recirculation flow rate. However, strict control of the steam temperature must be maintained to avoid thermal stress. Maintaining the steam temperature can be difficult due to heating value variation to the fuel source, time delay changes in the main steam temperature versus changes in fuel flow rate, difficulty of control of the main steam temperature control and the reheater steam temperature control system owing to the dynamic response characteristics of changes in steam temperature and the reheater steam temperature, and the fluctuation of inner fluid water and steam flow rates during the load-following operation. Up to the present time, the Proportional-Integral-Derivative Controller has been used to operate this system. However, it is very difficult to achieve an optimal PID gain with no experience, since the gain of the PID controller has to be manually tuned by trial and error. This paper focuses on the characteristic comparison of the PID controller and the modified 2-DOF PID Controller (Two-Degrees-Freedom Proportional-Integral-Derivative) on the DCS (Distributed Control System). The method is to design an optimal controller that can be operated on the thermal generating plant in Seoul, Korea. The modified 2-DOF PID controller is designed to enable parameters to fit into the thermal plant during disturbances. To attain an optimal control method, transfer function and operating data from start-up, running, and stop procedures of the thermal plant have been acquired. Through this research, the stable range of a 2-DOF parameter for only this system could be found for the start-up procedure and this parameter could be used for the tuning problem. Also, this paper addressed whether an intelligent tuning method based on immune network algorithms can be used effectively in tuning these controllers.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.2
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• pp.202-211
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• 2011

The stems and branchs of Euryale ferox Salisbury (EF), are used in Chinese herbal medicine for latent-heat-clearing, antipyretic, detoxicant and anti-inflammatory ailments. This plant is used worldwide for the treatment of many types of inflammatory disease including respiratory infections, diabetes mellitus, rheumatoid arthritis and play an important role in the immune reaction. Topical natural antioxidants are a useful strategy for the prevention of oxidative stress mediated inflammatory disease. Plants produce significant amounts of antioxidants to prevent the oxidative stress caused by photons and oxygen, therefore they represent a potential source of new compounds with antioxidant activity. This study was designed to evaluate whether EFEA (ethylacetate fraction of EF) may ameliorate oxidative stress and inflammatory status through the antioxidative mechanism in LPS-stimulated RAW 264.7 murine macrophage cell line. Treatment of RAW 264.7 cells with EFEA significantly reduced LPS-stimulated inflammatory response in a dose-dependent manner. In conclusion, the EF extracts have anti-inflammatory effects in vitro system, which can be used for developing pharmaceutical drug against oxidative stress and chronic inflammatory disease.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.111-111
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• 2018

Aronia (black chokeberry), a species of berries is source to a very large number of bioactive compounds like polyphenols, flavonoids, anthocyanins, and tannins in comparison to any other species. Owing to its antioxidant, anti-carcinogenic, anti-aging and anti-inflammatory properties. Fermentation- a bioconversion process exploiting the biological metabolic reaction of micro-organisms, has several benefits like improving the efficacy and safety of physiologically active substances, generation of new functional material, improving the adsorption rate and many others. Antigens like pathogens, food, pollen etc., generate a protective immune response in body tissues, and the process be referred to as inflammation. However, this when excessive results in a condition referred to as refractory inflammatory disease, whose incidence is increasing in the recent times, especially amongst children. The current study intended to assess the anti-oxidant activity, presence of polyphenols and anti-inflammatory efficacy of Aronia extract fermented by Lactic acid bacteria isolated from fermented sea foods. Aronia fruits collected from Sunchang, Chonbuk were lyophilized for fermentation. So as to maximise the efficacy of the fermented Aronia extract, the quantitative effects of lactic acid bacteria species, composition of extraction solution, influence of temperature and time on antioxidant activity and total polyphenol contents were investigated using an experimental design. Anti-inflammatory activity was evaluated on NO and cytokine ($TNF-{\alpha}$, IL-6) production in LPS activated Raw 264.7 cells. Results indicated that antioxidant effect and total polyphenol contents were best improved in extract of Aronia fermented by P. pentosaceus. In addition, NO and cytokine ($TNF-{\alpha}$, IL-6) levels were decreased significantly after fermentation. Thus, it was found that the anti-inflammatory activity of Aronia greatly increased after fermentation process using P. pentosaceus.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.336-340
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• 2008

Corilagin (CRN) isolated from Euphorbia helioscopia as rheumatoid arthritis drug. CRN was medicated to the abdominal cavity of collagen induced arthritis (CIA) mice that was an animal model for rheumatoid arthritis and its effects on incidence and arthritis index were studied. The results were as folllows; It was exhibited that medicating corilagin inhibited the infiltration of activated T lymphocytes into an inflammatory joint. The production of IgG and IgM that were RF (rheumatoid factor) and inflammatory cytokine, IL-6 and $TNF-{\alpha}$were reduced. After measuring $IFN-{\gamma}$and IL-4, it was found that it was shifted into Th2 immune response as increasing in IL-4. After liver function test, studies on liver poisoning of AST/ALT should be continued.

• Molecules and Cells
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• v.45 no.7
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• pp.502-511
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• 2022

Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.

• Journal of Ginseng Research
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• v.47 no.2
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• pp.183-192
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• 2023

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H₂S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

• Journal of Life Science
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• v.29 no.7
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• pp.809-816
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• 2019

The ubiquitous plant metabolite p-coumaric acid (p-CA) has antioxidant and anti-inflammatory properties, but its anti-cancer activity has not been established in gastric cancer cell lines. In this study, we investigated the effects of p-CA on the proliferation and transcriptome profile of SNU16 gastric cancer cells. Treatment with p-CA induced apoptosis of the SNU-16 cells by regulating the expression of pro-apoptotic and anti-apoptotic proteins, such as Bcl-2, poly (ADP-ribose) polymerase (PARP), Bax, procaspase-3, and cleaved-caspase-3. The genes differentially expressed in response to p-CA treatment of the SNU-16 cells were identified by RNA sequencing analysis. Genes regulated by p-CA were involved mainly in the inflammatory response, apoptotic processes, cell cycle, and immune response. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that the phosphatidylinositol-3-kinase-Akt and cancer signaling pathways were altered by p-CA. Protein-protein interaction (PPI) network analysis also revealed that p-CA treatment was correlated with differential expression of genes associated with the inflammatory response and cancer. Collectively, these results suggest that p-CA has potential utility in gastric cancer prevention.

• Molecules and Cells
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• v.39 no.5
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• pp.426-438
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• 2016

Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2439-2445
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• 2014

Cryptotanshinone (CPT), is a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miotiorrhiza bunge. Numerous researchers have found that it could work as a potent antitumor agent to inhibit tumor growth in vitro, buith there has been much less emphasis on its in vivo role against breast tumors. Using a mouse tumor model of MCF7 cells, we showed that CPT strongly inhibited MCF7 cell growth in vivo with polarization of immune reactions toward Th1-type responses, stimulation of naive CD4+ T cell proliferation, and also increased IFN-${\gamma}$ and perforin production of CD4+ T cells in response to tumor-activated splenocytes. Furthermore, data revealed that the cytotoxic activity of CD4+ T cells induced by CPT was markedly abrogated by concanamycin A(CMA), a perforin inhibitor, but not IFN-${\gamma}$ Ab. On the other hand, after depletion of CD4+ T cells or blocked perforin with CMA in a tumor-bearing model, CPT could not effectively suppress tumor growth, but this phenomenon could be reversed by injecting naive CD4+ T cells. Thus, our results suggested that CPT mainly inhibited breast tumor growth through inducing cytotoxic CD4+ T cells to secrete perforin. We further found that CPT enhanced perforin production of CD4+ T cells by up-regulating JAK2 and STAT4 phosphorylation. These findings suggest a novel potential therapeutic role for CPT in tumor therapy, and demonstrate that CPT performs its antitumor functions through cytotoxic CD4+ T cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.4
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• pp.853-859
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• 2009

Nardostachys chinensis has been used widely as a traditional medicine for the treatment of diverse diseases. The dried plant was extracted with 85% methanol extract (NC). We investigated the antioxidant properties of NC on the 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, superoxide anion and nitric oxide radical scavenging capacity under in vitro assays. NC showed potent antioxidant activity, compared to ascorbic acid. In macrophages, nitric oxide is released as an inflammatory mediator and has been proposed to be an important modulator of many pathophysiological conditions in inflammation. In the present study, it was also investigated that the inhibition effects on NO and the mechanism of down-regulation of immune response by NC in IFN-IFN-$\gamma$/LPS-stimulated mouse (C57BL/6) peritoneal macrophages. Extracts of NC suppressed NO production and the expression of iNOS and COX-2. The present results indicate that NC has an antioxidant and anti-inflammatory properties and therefore may be beneficial in diseases which related to oxidative stress-mediated chronic inflammatory disorders.