• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.253-263
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• 2005

This paper proposed a mobile multicast technique to satisfy end-to-end QoS for various user requirements in mobile network environment. In order to provide seamless mobility, fast handoff technique was applied. By using L2 mobile trigger, it was possible to minimize remarkable amount of packet loss by delay occurred during handoff. To provide efficient multicast, concept of hierarchy was introduced to Xcast++, which results in a creation of HXcast++. HXcast++ optimized transfer path of multicast and reduced expensive multicast maintenance costs caused by frequent handoff. Suggestion of GMA (Group Management Agent) mechanism allows joining to group immediately without waiting IGMP Membership query during handoff. GMA mechanism will minimize the delay for group registration process and the resource usage due to delay of withdrawal process. And also use of buffering & forwarding technique minimized packet loss during generation of multicast tree. IntServ/RSVP was used to provide End-to-End QoS in local domain and DiffServ was used in global domain. To minimize reestablishment of RSVP session delay, extended HXcast++ control messages ware designed to require PATH message. HXcast++ proposed in this thesis is defined as multicast technique to provide end-to-end QoS and also to satisfy various user requirements in mobile network environment.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1269-1278
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• 2013

Crack remediation on the surface of cement mortar using microbiological calcium carbonate ($CaCO_3$) precipitation (MICP) has been investigated as a microbial sealing agent on construction materials. However, MICP research has never acknowledged the antifungal properties of calcite-forming bacteria (CFB). Since fungal colonization on concrete surfaces can trigger biodeterioration processes, fungi on concrete buildings have to be prevented. Therefore, to develop a microbial sealing agent that has antifungal properties to remediate cement cracks without deteriorative fungal colonization, we introduced an antifungal CFB isolated from oceanic islands (Dokdo islands, territory of South Korea, located at the edge of the East Sea in Korea.). The isolation of CFB was done using B4 or urea-$CaCl_2$ media. Furthermore, antifungal assays were done using the pairing culture and disk diffusion methods. Five isolated CFB showed $CaCO_3$ precipitation and antifungal activities against deteriorative fungal strains. Subsequently, five candidate bacteria were identified using 16S rDNA sequence analysis. Crack remediation, fungi growth inhibition, and water permeability reduction of antifungal CFB-treated cement surfaces were tested. All antifungal CFB showed crack remediation abilities, but only three strains (KNUC2100, 2103, and 2106) reduced the water permeability. Furthermore, these three strains showed fungi growth inhibition. This paper is the first application research of CFB that have antifungal activity, for an eco-friendly improvement of construction materials.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.5
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• pp.413-420
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• 2015

Dexmedetomidine is a sedative and analgesic agent that exerts its effects by selectively agonizing ${\alpha}2$ adrenoceptor. Histamine is a pathophysiological amine that activates G protein-coupled receptors, to induce $Ca^{2+}$ release and subsequent mediate or progress inflammation. Dexmedetomidine has been reported to exert inhibitory effect on inflammation both in vitro and in vivo studies. However, it is unclear that dexmedetomidine modulates histamine-induced signaling and pro-inflammatory cytokine expression. This study was carried out to assess how dexmedetomidine modulates histamine-induced $Ca^{2+}$ signaling and regulates the expression of pro-inflammatory cytokine genes encoding interleukin (IL)-6 and -8. To elucidate the regulatory role of dexmedetomidine on histamine signaling, HeLa cells and human salivary gland cells which are endogenously expressed histamine 1 receptor were used. Dexmedetomidine itself did not trigger $Ca^{2+}$ peak or increase in the presence or absence of external $Ca^{2+}$. When cells were stimulated with histamine after pretreatment with various concentrations of dexmedetomidine, we observed inhibited histamine-induced $[Ca^{2+}]_i$ signal in both cell types. Histamine stimulated IL-6 mRNA expression not IL-8 mRNA within 2 hrs, however this effect was attenuated by dexmedetomidine. Collectively, these findings suggest that dexmedetomidine modulates histamine-induced $Ca^{2+}$ signaling and IL-6 expression and will be useful for understanding the antagonistic properties of dexmedetomidine on histamine-induced signaling beyond its sedative effect.

• Journal of Korea Association of Health Promotion
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• v.2 no.2
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• pp.154-159
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• 2004

Rheumatoid arthritis(RA) is the most common inflammatory joint disease and a major cause of disability, morbidity, and mortality. It occurs worldwide, affecting approximately one percent of adults. Inflammation of the synovial membrane surrounding a joint leads to swollen, tender, and stiff joints RA has no known cure and the diagnosis is made based on clinical criteria and many different options exist for treatment. All of these factors magnify the importance of the patient-physician interaction and place a premium on the art rather than the science of medicine. The major goals of therapy for RA are to relive pain, swelling, and fatigue; improve joint function; stop joint daage, and prevent disability and disease-related morbidity. Some combination of nonsteroidal anti-inflammatory drugs(NSAIDs), steroids, and DMARDs is necessary in almost patients. In many combinations of different DMARDs or DMARDs plus biologicals are necessary for optimal control. Additionaly, all patients with RA should be educated about their disease and the therapies that will be used. Patient education is essentially early in the disease course and on going basis Much research is focused on the further development of biological agent for treatment of RA. Elucidation of the trigger or trigers for RA may allow us to begin to think about prevention of RA.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.61-67
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• 2012

In the present study, effects of sun ginseng (SG) on the collagen synthesis and the proliferation of dermal fibroblast were investigated. Collagen synthesis was measured by assaying procollagen type I C-peptide production. In addition, the level of matrix metalloproteinase (MMP)-1 was assessed by western blot analysis. SG suppressed the MMP-1 protein level in a dose-dependent manner. In contrast, SG dose-dependently increased tissue inhibitors of MMP (TIMP)-1 production in fibroblasts. SG increased type I collagen production directly and/or indirectly by reducing MMP-1 and stimulating TIMP-1 production in human dermal fibroblasts. SG dose-dependently induced fibroblast proliferation and this, in turn, can trigger more collagen production. These results suggest that SG may be a potential pharmacological agent with anti-aging properties in cultured human skin fibroblast.

• Mycobiology
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• v.40 no.1
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• pp.59-65
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• 2012

Antagonistic microorganisms against $Rhizoctonia$ $solani$ were isolated and their antifungal activities were investigated. Two hundred sixteen bacterial isolates were isolated from various soil samples and 19 isolates were found to antagonize the selected plant pathogenic fungi with varying degrees. Among them, isolate C9 was selected as an antagonistic microorganism with potential for use in further studies. Treatment with the selected isolate C9 resulted in significantly reduced incidence of stem-segment colonization by $R.$ $solani$ AG2-2(IV) in Zoysia grass and enhanced growth of grass. Through its biochemical, physiological, and 16S rDNA characteristics, the selected bacterium was identified as $Bacillus$ $subtilis$ subsp. $subtilis$. Mannitol (1%) and soytone (1%) were found to be the best carbon and nitrogen sources, respectively, for use in antibiotic production. An antibiotic compound, designated as DG4, was separated and purified from ethyl acetate extract of the culture broth of isolate C9. On the basis of spectral data, including proton nuclear magneric resonance ($^1H$ NMR), carbon nuclear magneric resonance ($^{13}C$ NMR), and mass analyses, its chemical structure was established as a stereoisomer of acetylbutanediol. Application of the ethyl acetate extract of isolate C9 to several plant pathogens resulted in dose-dependent inhibition. Treatment with the purified compound (an isomer of acetylbuanediol) resulted in significantly inhibited growth of tested pathogens. The cell free culture supernatant of isolate C9 showed a chitinase effect on chitin medium. Results from the present study demonstrated the significant potential of the purified compound from isolate C9 for use as a biocontrol agent as well as a plant growth promoter with the ability to trigger induced systemic resistance of plants.

• Korean Journal of Medicinal Crop Science
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• v.17 no.5
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• pp.321-327
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• 2009

Sunlight, and in particular its UV component, is the major environmental trigger that underlies the major signs of human skin and skin cancer in general. Therefore, this study was carried out to investigate the UV protection effects of R. coreanus. R. coreanus was extracted by ultra high pressure extraction process at 500 MPa and $30^{\circ}C$ for 5 and 15 minutes. The cytotoxicity of the extracts extracted by ultra high pressure process on human dermal fibroblast cell CCD-986sk, human kidney normal cell HEK293, and human lung normal cell HEL299 was measured as 17.5%, 16.5% and 14.0%, respectively in adding $1.0\;mg/m{\ell}$ of the samples, which was much lower than that from conventional water extraction method at $100^{\circ}C$ as 23.2%, 22.5%, 21.2%. The secretion of $NO^-$ from macrophage showed $15.9\;{\mu}M$ on the R. coreanus extract from this process, which was higher than others. Prostaglandin $E_2$ ($PGE_2$) production from UV-induced human skin cells was also greatly decreased down to $510\;pg/m{\ell}$, compared to the control. From the results, we considered that the extracts from R. coreanus could be potent natural materials for skin anti-inflammation agent, and could be used as a potential anti-aging for the photo-damaged skin.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.758-765
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• 2007

In this paper, we propose an efficient seamless handoff scheme to minimize packet loss and unnecessary packets on the Internet using the peculiar mobility characteristics of public vehicles such as trains. MR (Mobile Router) in a train visits each AR (Access Router) in the fixed order. As the MR detects reachability to the NAR (Next Access Router) on the new link, the PAR (Previous Access Router) can directly deliver packets from MR's HA (Home Agent) to the NAR according to the HML (Handoff Mobile router List). Then. the NAR buffers them until the MR finishes L3 (Layer 3) handoff procedure with the NAR. Therefore, our scheme can support a seamless handoff without the packet loss and unnecessary packets on the Internet. The result of our performance evaluation has shown that the proposed scheme could provide excellent performance, compared with the NEMO basic support protocol and the Bi-casting protocol.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.22-26
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• 2014

Protocatechualdehyde (PA) is phenolic compound having antioxidative and antitumor activities. PA was purified from supernatant of Streptomyces lincolnensis M-20. In the presence of copper ion, PA acted as pro-oxidant. The antioxidant activity was assessed with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, and the pro-oxidant effect of PA on DNA damage as pBR322 plasmid DNA-cleaving agents in the presence of Cu(II) ions was investigated. The involvement of reactive oxygen species (ROS) in the DNA damage was confirmed by the inhibition of the DNA breakage by using glutathione (GSH), specific scavenger of ROS. When the increase in ROS reaches a certain level (the toxic threshold), it may trigger cell death. The formation of the PA/Cu(II) chelate complex was confirmed by reaction with ethylenediamine-tetraacetic acid (EDTA), a well-known chelating agent for metal ions, by using UV/Vis spectroscopic analysis.

• KSBB Journal
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• v.29 no.1
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• pp.36-41
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• 2014

Skin disease is one of the most common diseases and its incidence is increasing dramatically in modern society. Specially, many attempts have been made to treat chronic skin inflammation diseases, such as psoriasis and atopic dermatitis, but effective therapies for the immune cell-mediated skin diseases, including psoriasis and atopic dermatitis have not been developed. Until recently, several drug candidates which were claimed to be effective for skin diseases have been reported, but most of them are not used to treat chronic skin disease. Especially, Psoriasis is characterized by excessive growth and aberrant differentiation of keratinocytes, but is fully reversible with appropriate therapy. The trigger of the keratinocyte response is thought to be activation of the cellular immune system, with T cells and various immune-related cytokines. Formation of new blood vessels starts with early psoriatic changes and disappears with disease clearance. Several angiogenic mediators are up-regulated in psoriasis development. Contact- and mediator-dependent factors derived from keratinocytes, mast cells and immune cells may contribute to the strong blood vessel formation of psoriasis. New technologies and experimental models provide new insights into the role of angiogenesis in psoriasis pathogenesis. TMP and its derivatives themselves effectively inhibited in vitro cell migration, tube formation, and the expression of angiogenic factors. However, TMP and its derivatives induced side effects including hemolysis and local side effects. Therefore, in an attempt to reduce the toxicity and the undesirable side effects of TMP and derivatives, a liposomal formulation was prepared and tested for its effectiveness. TMP and derivatives liposomes retained the effectiveness of TMP in vitro while side effects were reduced. These results support the conclusion that TMP effectively inhibits in vitro angiogenesis, with the possibility that use as a psoriasis relief agent.