• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.6
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• pp.91-102
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• 2017

The early basic studies on RDE has been surveyed in the previous paper. Recently active researches are carrying on for the application to the power plant and aerospace propulsion systems. Collaboration researches are going on for the application of RDE for the gas turbine, liquid rocket and combined cycle engines in many countries. Following the previous Part 1 paper, present paper is intended to provide the comprehensive survey of recent worldwide efforts on the realistic application of RDE.

• Microbiology and Biotechnology Letters
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• v.51 no.2
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• pp.174-183
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• 2023

Various skin diseases are occurring due to external factors such as urbanization and increase in environmental pollution and wearing masks due to COVID-19. Accordingly, various functional cosmetics are being released, but as some side effects are reported, research on functional cosmetics materials using natural plants is necessary. Therefore, in this study, the antioxidant, antibacterial and anti-inflammatory effects of Phyllanthus emblica, Geranium (Pelargonium graveolens), and Commiphora myrrha mixed extracts (PGC) that pharmacological efficacy has been verified were analyzed and their potential as functional cosmetics raw materials was examined. Four extracts (PGC-1~4) were prepared according to the extraction method. ABTS and DPPH radical scavenging activity experiments were conducted for the antioxidant efficacy of the extracts. In addition, paper disc experiments and LPS inflammation-inducing cytokine experiments were conducted to examine the antibacterial and anti-inflammatory effects. In addition, a cell viability test was performed to confirm cytotoxicity. As results of the study, all extracts showed antioxidant, antibacterial, and anti-inflammatory effects without cytotoxicity, and in particular, PGC-4, a fermentation and ultrasonic extract, showed the best efficacy. This means that the extraction yield of useful components varies depending on the extraction method.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.384-391
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• 2016

In previous studies, we confirmed that the ethanol extract of Polygonatum sibiricum (ID1216) has anti-obesity effects on high-fat diet-fed mice. To identify the obesity-related genes affected by ID1216, we studied its effects both in vivo and in vitro. In mice, single administration of ID1216 increased the expression of obesity-related genes including sirtuin1 (SIRT1), peroxisome proliferator-activated receptor ${\gamma}$ coactivator $1{\alpha}$ ($PGC1{\alpha}$) and peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) compared to that in mice administered the vehicle; their downstream genes (uncoupling proteins, acyl-CoA oxidase, adipocyte protein 2, and hormone-sensitive lipase) were also increased by ID1216. In fully differentiated 3T3-L1 adipocytes, ID1216 showed the same effects on anti-obesity genes as those in the animal model. Based on these results, we propose that ID1216 has anti-obesity effects by regulating the $SIRT1-PGC1{\alpha}-PPAR{\alpha}$ pathway and their downstream genes, thereby controlling energy and lipid metabolisms.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.363-366
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• 2012

Detonative combustion is considered as a promising combustion mechanism for improving thermodynamic efficiency of power generation systems as a PGC, as well as high-speed propulsion systems. Among the various types of detonative combustion, RDE is fascinated by many researchers because of the simplicity and continuos operation characteristics. Present paper is an introduction to the physical and operational concept of RDE with a brief history of RDE researches and recent development activities. Additional discussions will devoted to the relevance to the tangential mode instabilities in liquid rocket engines and improvement of liquid rocket performance.

• BMB Reports
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• v.47 no.5
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• pp.280-285
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• 2014

Cancer cells undergo uncontrolled proliferation, and aberrant mitochondrial alterations. Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial heat shock protein. TRAP1 mRNA is highly expressed in some cancer cell lines and tumor tissues. However, the effects of its overexpression on mitochondria are unclear. In this study, we assessed mitochondrial changes accompanying TRAP1 overexpression, in a mouse cell line, NIH/3T3. We found that overexpression of TRAP1 leads to a series of mitochondrial aberrations, including increase in basal ROS levels, and decrease in mitochondrial biogenesis, together with a decrease in peroxisome proliferator-activated receptor gamma coactivator-$1{\alpha}$ (PGC-$1{\alpha}$) mRNA levels. We also observed increased extracellular signal-regulated kinase (ERK) phosphorylation, and enhanced proliferation of TRAP1 overexpressing cells. This study suggests that overexpression of TRAP1 might be a critical link between mitochondrial disturbances and carcinogenesis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.23-30
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• 2008

Mitochondria biogenesis requires a coordination of two genomes, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA). Disruption of mitochondria function leads to a loss of mitochondrial membrane potential and ATP generating capacity and consequently results in chronic degenerative diseases including insulin resistance, metabolic syndrome and neurodegenerative diseases. Although PPAR-${\gamma}$ coactivator-$1{\alpha}$ (PGC-$1{\alpha}$) was discovered as a central regulator of mitochondria biogenesis and a transcriptional co-activator of nuclear respiratory factor (NRF) and mitochondrial transcription factor A (Tfam), the expressions of PGC-$1{\alpha}$, NRF and Tfam were not significantly altered in tissues showing abnormal mitochondria functions. This observation suggests that there should be another regulator(s) for mitochondria function. Here, we demonstrate microRNAs (miRNAs) can modulate mitochondria function. Overexpression of microRNA dissipated mitochondrial membrane potential and increased ROS production in vitro and in vivo. It will be discussed the target of microRNA and its role in metabolic syndrome.

• Korean Journal of Exercise Nutrition
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• v.23 no.4
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• pp.32-35
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• 2019

[Purpose] Fibronectin type III domain containing 5 (FNDC5)/irisin is an exercise-induced myokine, which contributes to cognitive functions. However, the relationship between the neuroprotective effects of FNDC5/irisin and hippocampal dendritic remodeling and astrocyte-secreted factors remains unclear. Therefore, we explored whether subchronic recombinant irisin treatment affected hippocampal morphology and some astrocyte-derived molecules. [Methods] Mice were intraperitoneally injected with irisin (0.5 μg/kg/day) for seven days, followed by their sacrifice two days later. Hippocampal morphometric parameters were analyzed and pgc-1a, fndc5, bdnf, and some astrocyte-derived factors mRNA levels were measured. [Results] Dendritic length, arborization, and spine density were enhanced by irisin regimen in hippocampal CA1 and CA3 areas. Hippocampal pgc-1a, fndc5, and bdnf mRNA levels were significantly increased by irisin treatment. Moreover, hevin mRNA levels were significantly enhanced, whereas tgf-b1 levels downregulated by irisin treatment. [Conclusion] FNDC5/irisin has dendritogenic activity probably through hevin induction and TGF-β1 suppression.

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.454-454
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• 2021

• Journal of Periodontal and Implant Science
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• v.43 no.3
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• pp.130-135
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• 2013

Purpose: The purpose of this study was to evaluate the tensile strength of surgical synthetic absorbable sutures over a period of 14 days under simulated oral conditions. Methods: Three suture materials (polyglycolic acid [PGA], polyglactin [PG] 910, and poly (glycolide-co-${\epsilon}$-caprolactone) [PGC]) were used in 4-0 and 5-0 gauges. 210 suture samples (35 of each material and gauge) were used. All of the samples were tested preimmersion and 1 hour and 1, 3, 7, 10, and 14 days postimmersion. The tensile strength of each suture material and gauge was assessed. The point of breakage and the resorption pattern of the sutures were also assessed. Results: During the first 24 hours of immersion, all 4-0 and 5-0 samples of PGA, PG 910, and PGC maintained their initial tensile strength. At baseline (preimmersion), there was a statistically significant (P<0.001) difference in the tensile strengths between the 4-0 and 5-0 gauge of PGA, PG 910, and PGC. PGA 4-0 showed the highest tensile strength until day 10. At 7 days, all the 4-0 sutures of the three materials had maintained their tensile strength with PGA 4-0 having significantly greater (P=0.003) tensile strength compared to PG. Conclusions: 4-0 sutures are stronger and have greater tensile strength than 5-0 sutures. The PGA 4-0 suture showed the highest tensile strength at the end of day 10.

• Journal of Aquaculture
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• v.16 no.4
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• pp.240-244
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• 2003

The primitive gonad development in Paralichthys olivaceus was classified into (ⅰ) primordial germ cell (PGC), (ⅱ) genital ridge type (GRT), (ⅲ) primitive gonad type I (PGT I) and (ⅳ) primitive gonad type II stages. In the control group, PGC was recognizable on the 3rd days after hatching, and the primodial gonad after 24th days, while it was around the 22nd day after hatching in the group exposed to PCBs 3.0 $\mu\textrm{g}$/L for 30 days. Likewise, the progress of kidney development was recognized in four stages; unitubular type of mesonephric duct (UTMD), the branched mesonephric duct (BMD), convoluted tubule formation (CTF) and glomerulus appearing (GA) stage. It was structurally completed between the 25th and 30th day after hatching in two groups. There was no significant difference (p>0.05) in the time scale of development of gonad, and kidney between control and the PCBs - exposed group.