• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.187-197
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• 1998

To investigate the spray behavior and atomization characteristics using an air-assist injector, spray visualization and PDPA measurements were carried out under the various assisted air pressures and the fixed fuel pressure. The air assist pintle type injector employed in this study is consisted of the air assist adaptor and an injector housing using the gasoline fuel and air as the working fluids. As results, increasing pressure of assisted air, the growth of spray tip penetration is gradually reduced at the end of spray and spray angle is steadily increased at the main spray region except from the early spray. For the air assist pressure of 25㎪ in a spray downstream, it is doncluded that droplet size distribution shows the peak of 10${\mu}{\textrm}{m}$ and most of the droplet sizes are less than 50${\mu}{\textrm}{m}$. Also, the air-assist injector extremely improves fuel atomization in order to produce much finer droplets, it shows that approximately, in this case, 50% decreade of SMD than without air assit.

• YAKHAK HOEJI
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• v.56 no.1
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• pp.26-34
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• 2012

Mast cells play an important role in early and late phase allergic reactions through allergen and IgE-dependent release of histamine, proteases, prostaglandins, and several multifunctional cytokines. In this study, we investigated whether Cudrania tricuspidata extract (CTE) suppresses IgE-mediated allergic responses in mast cells, an allergic animal model, and its mechanism of action in mast cells. We found that CTE inhibited IgE-mediated degranulation and cytokine production in rat basophilic leukemia (RBL)-2H3 mast cells and bone marrow-derived mast cells (BMMC), as well as passive cutaneous anaphylaxis (PCA) in mice. With regard to its mechanism of action, CTE suppressed the activating phosphorylation of spleen tyrosine kinase (Syk), a key enzyme in mast cell signaling processes and that of LAT, a downstream adaptor molecule of Syk in $Fc{\varepsilon}RI$-mediated signal pathways. CTE also suppressed the activating phosphorylation of mitogen-activated protein (MAP) kinases and Akt. The present results strongly suggest that the anti-allergic activity of CTE is mediated through inhibiting degranulation and allergic cytokine secretion by inhibition of Syk kinase in mast cells. Therefore, CTE may be useful for the treatment of allergic diseases.

• Molecules and Cells
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• v.41 no.8
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• pp.753-761
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• 2018

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is identified as a signaling adaptor protein that regulates bone metabolism, immunity, and the development of several tissues. Therefore, its functions are closely associated with multiple diseases. TRAF6 is also involved in the regulation of hematopoiesis under steady-state conditions, but the role of TRAF6 in modulating hematopoietic stem and progenitor cells (HSPCs) during the developmental stages remains unknown. Here, we report that the deletion of TRAF6 in hematopoietic lineage cells resulted in the upregulation of HSPCs in the fetal liver at the prenatal period. However, in the early postnatal period, deletion of TRAF6 drastically diminished HSPCs in the bone marrow (BM), with severe defects in BM development and extramedullary hematopoiesis in the spleen being identified. In the analysis of adult HSPCs in a BM reconstitution setting, TRAF6 played no significant role in HSPC homeostasis, albeit it affected the development of T cells. Taken together, our results suggest that the role of TRAF6 in regulating HSPCs is altered in a spatial and temporal manner during the developmental course of mice.

• The Korea Journal of Herbology
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• v.30 no.1
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• pp.77-84
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• 2015

Objectives : Brain inflammation early activates the microglia and activated microglia secrete a variety of pro-inflammatory cytokines. Kaempferol, which is a flavonoid in Cuscutae Semen, shows a wide range of physiological activities, including neurons protection and anti-inflammatory actions through inhibition of pro-inflammatory mediators. The present study examined the modulatory effect of kaempferol on cytokines [tumor necrosis factor- alpha ($TNF-{\alpha}$), interleukin-1beta ($IL-1{\beta}$) and interleukin-6 (IL-6)] and cyclooxygenase-2 (COX-2) mRNA expression and microglia activation in the brain tissue of the mouse. Methods : Kaempferol was administered orally three doses of 10, 20 and 30 mg/kg respectively, once 1 hour before the lippolysaccharide(LPS) (3 mg/kg, i.p.) injection. Brain tissue was removed at 4 hours after LPS injection. Cytokines and COX-2 mRNA expression in the brain tissue was measured by the quantitative real-time polymerase chain reaction (PCR) method. Iba1 expression was calculated by western blotting method. Microglia was observed with immunohistochemistry. Immunohistochemistry stained microglia was analyzed by using ImageJ software. Results : Kaempferol 20 and 30 mg/kg was significantly attenuated the expression of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 mRNA. Kaempfrol 10, 20 and 30 mg/kg significantly attenuated COX-2 mRNA expression in the brain tissue. Kaempferol 30 mg/kg significantly suppressed the increase of Iba1 protein expression by LPS. Kaempferol 30 mg/kg significantly decreased the number of microglia in the cerebral cortex and the number and cell size of microglia in the hypothalamic region and the area percentage of ionized calcium binding adaptor molecule 1(Iba1)-expressed microglia in the hippocampus. Conclusions : This results indicate that kaempferol plays an anti-inflammatory role in the brain.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.145-153
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• 2013

Objectives : Neuroinflammation is characterized by microglial activation and the expression of major inflammatory mediators. The present study investigated the inhibitory effect of ginsenoside Rg1 ($GRg_1$), a principle active ingredient in Panax ginseng, on pro-inflammatory cytokines and microglial activation induced by systemic lipopolysaccharide (LPS) treatment in the mouse brain tissue. Methods : Varying doses of $GRg_1$ was orally administered (10, 20, and 30 mg/kg) 1 h before the LPS injection (3 mg/kg, intraperitoneally). The mRNA expression of pro-inflammatory cytokines in the brain tissue was measured using the quantitative real-time PCR method at 4 h after the LPS injection, Microglial activation was evaluated using western blotting and immunohistochemistry against ionized calcium binding adaptor molecule 1 (Iba1) in the brain tissue. Cyclooxigenase-2 (COX-2) expressions also observed using western blotting and immunohistochemistry at 4 h after the LPS injection, In addition, double-immunofluorescent labeling of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and COX-2 with microglia and neurons was processed in the brain tissue. Results : $GRg_1$ (30 mg/kg) significantly attenuated the upregulation of TNF-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-6 mRNA in the brain tissue at 4 h after LPS injection. Morphological activation and Iba1 protein expression of microglia induced by systemic LPS injection were reduced by the $GRg_1$ (30 mg/kg) treatment. Upregulation of COX-2 protein expression in the brain tissue was also attenuated by the $GRg_1$ (30 mg/kg) treatment. Conclusion : The results suggest that $GRg_1$ is effective in the early stage of neuroinflammation which causes neurodegenerative diseases.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.75-88
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• 2005

Ameloblastoma is the most commonly occurring odontogenic tumor in oral cavity. Although most are benign epithelial neoplasm, they are generally considered to be locally aggressive and destructive, exhibiting a high rate of recurrence. The biological behavior of this neoplasm is a slowly growing, locally invasive tumor without metastasis, therefore malignant neoplasm, changed its histological appearance to carcinoma or showed distant metastasis, is only defined clinically. In this study, we identified the differentially expressed genes(DEGs) in stages under benign or malignant ameloblastoma compared with normal patient using ordered differential display(ODD) reverse transcription(RT)-PCR and $GeneFishing^{TM}$ technology. ODD RT-PCR is rather effective when the investigation of samples containing very small amounts of total RNA must be accomplished. ODD RT-PCR used the means of amplification with anchored T-primer and adaptor specific primer. bearing definite two bases at their 3' ends and so this method could display differential 3'-expressed sequence taqs(ESTs) patterns without using full-length cDNAs. Compared with standard differential display, ODD RT-PCR is more simple and have enough sensitivity to search for molecular markers by comparing gene expression profiles, However, this method required much effort and skill to perform. $GeneFishing^{TM}$ modified from DD-PCR is an improved method for detecting differentially expressed genes in two or more related samples. This two step RT-PCR method uses a constant reverse primer(anchor ACP-T) to prime the RT reaction and arbitrary primer pairs(annealing control primers, ACPs) during PCR. Because of high annealing specificity of ACPs than ODD RT-PCR, the application of $GeneFishing^{TM}$ to DEG discovery generates reproducible, authentic, and long(100bp to 2kb) PCR products that are detectable on agarose gels. Consequently, various DEGs observed differential expression levels on agarose gels were isolated from normal, benign, and malignant tissues using these methods. The expression patterns of the some isolated DEGs through ODD RT-PCR and $GeneFishing^{TM}$ were confirmed by Northern blot analysis and RT-PCR. The results showed that these identified DEGs were implicated in ameloblastoma neoplasm processes. Therefore, the identified DEGs will be further studied in order to be applied in candidate selection for marker as an early diagnosis during ameloblastoma neoplasm processes.