• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.216-216
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• 2022

The starch-branching enzymes (BEs) are responsible for synthesizing the amylopectin, which plays an important role in determining the structural and physical properties of starch granules. BE has two differently functioning isoforms (BEI and BEIIa/b) based on their difference in the chain-length pattern by the degree of polymerization (DP), which mainly contributes to the amylopectin chain length distribution in starch biosynthesis. In this study, we investigated functional haplotypes and evolutionary analyses of SBE1 in 374 rice accessions (320 Korean bred and 54 wild). The analyses were performed based on the classified subpopulations. Haplotype analysis generates a total of 8 haplotypes, of which only four haplotypes were functional carrying four functional SNPs in four different exons of SBE1 on chromosome 6. Nucleotide diversity analysis showed a highest pi-value in aromatic group (0.0029), while the lowest diversity value was in temperate japonica (0.0002), indicating the signal of this gene evolution origin. Different directional selections could be estimated by negative Tajima's D value of temperate japonica (-1.1285) and positive Tajima's D value of tropical japonica (0.9456), where the selective sweeps were undergone by both positive purifying and balancing selections. Phylogenetic analysis indicates a closer relationship of the wild with most of the cultivated subgroups indicating a common ancestor for SBE1 gene. FST-values indicate distant genetic relationships of temperate japonica from all other classified groups. PCA and population structure analysis show an admixed structure of wild and cultivated subpopulations in some proportions.

• Biomolecules & Therapeutics
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• v.32 no.3
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• pp.319-328
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• 2024

Lysophosphatidic acid receptor 1 (LPA₁) plays a critical role in brain injury following a transient brain ischemic stroke. However, its role in permanent brain ischemic stroke remains unknown. To address this, we investigated whether LPA₁ could contribute to brain injury of mice challenged by permanent middle cerebral artery occlusion (pMCAO). A selective LPA₁ antagonist (AM152) was used as a pharmacological tool for this investigation. When AM152 was given to pMCAO-challenged mice one hour after occlusion, pMCAO-induced brain damage such as brain infarction, functional neurological deficits, apoptosis, and blood-brain barrier disruption was significantly attenuated. Histological analyses demonstrated that AM152 administration attenuated microglial activation and proliferation in injured brain after pMCAO challenge. AM152 administration also attenuated abnormal neuroinflammatory responses by decreasing expression levels of pro-inflammatory cytokines while increasing expression levels of anti-inflammatory cytokines in the injured brain. As underlying effector pathways, NF-κB, MAPKs (ERK1/2, p38, and JNKs), and PI3K/Akt were found to be involved in LPA₁-dependent pathogenesis. Collectively, these results demonstrate that LPA₁ can contribute to brain injury by permanent ischemic stroke, along with relevant pathogenic events in an injured brain.

• The Journal of Internal Korean Medicine
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• v.29 no.4
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• pp.1048-1060
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• 2008

Cirsii Japonici Herba(CJ) is a wild perennial herb found in many areas of Korea as well as China and Japan, which has been used to treat bleeding and inflammation. Silibinin is the main flavonoid extracted from milk thistle (Cirsii Japonici Herba). It exhibits potent antioxidant activity and anti-inflammatory effect. In this study, the effect of CJ and silibinin extract on lipopolysaccharide-induced inflammation was investigated using MTS assay, RT-PCR, western blot, and nitric oxide detection on mouse BV2 microglial cell lines. In the present results, CJ and silibinin extract suppressed nitric oxide production by inhibiting the lipopolysaccharide-stimulated enhancement of COX-2 and iNOS gene expression in BV2 cells. Moreover, CJ and silibinin also repressed some lipopolysaccharide-induced signaling molecules. Importantly, catalase-induced COX-2 and iNOS expression needed activations of $NF-{\kappa}B$, PI3K/Akt, and MAPK, which were important for the transcriptional up-regulation of COX-2 and iNOS. CJ and silibinin interaction on BV2 cells down-regulated $NF-{\kappa}B$-dependent proinflammatory cytokine (IL-2,IL-6) expression. They are involved in the regulation of inflammatory responses. These data shows that CJ and silibinin exerts anti-inflammatory and analgesic effects, probably by suppression of COX-2 and iNOS synthase expression in BV2 microglial cells.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.939-945
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• 2003

Seventeen Chinese indigenous pig breeds and three introduced pig breeds had been carried out by means of vertical polyacrylamide gel electrophoresis (PAGE). According to the results, eight serum protein loci were highly polymorphic except Pi-2 and Cp. The polymorphism information content (PIC) of Hpx was the highest (0.5268), while that of Cp was the lowest (0.0257). The population genetic variation index showed that about 84% genetic variation existed in the population, and the rest of 16% distributed between the populations. The genetic variation of Yimeng black pig and Duroc were the highest and the lowest, respectively. The genetic variation of Chinese indigenous pig breeds was much more than that of exotic groups. Genetic distance results showed that Chinese indigenous pig breeds were classified into four groups with the three introduced pig breeds clustered into another group. The results also supported the geographic distribution of Chinese indigenous pig breeds in certain extent.

• Transactions of the Korean Society of Mechanical Engineers
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• v.7 no.4
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• pp.425-433
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• 1983

Fatigue tests by axial loading (R=0.1) were carried out to investigate fatigue crack growth properties of small surface cracks in mild steel at room temperature, 250.deg. C and 400.deg. C, by using flat specimens with a small artificial pit. All the data of the fatigue crack growth rate obtained in the present tests are determined as a function of the stress intensity factor range, so that the applicability of liner fracture mechanics to the fatigue crack growth of surface cracks at elevated temperatures is investigated and discussed in comparison with the data of type 304 stainless steel at room temperature and elevated temperature. The obtained results are as follows: 1) Relations of both surface fatigue crack length and its depth to cycle ratio fall within a narrow scatter band in spite of different stress levels. 2) The .DELTA. .sigma. .root. .pi. a-da/dN relation of surface fatigue crack growth at room temperature is independent of the stress level and can be plotted as a straight line at log-log diagram, but the relation at 400.deg. C depends partly on the stress level. 3) Relations of the fatigue crack growth into depth d(2b)/dN and is stress intensity factor range .DELTA. $K_{I}$, accounted for the aspect ratio variation, fall within a narrow scatter band for wide range of the applied stress levels. And .DELTA. $K_{I}$E-d(2b)/dN relations of mild steel at different stress level coincide relatively well with the data of type 304 stainless steel. 4) The value of aspect ratio obtained by a beach mark method and a temper coloring method approaches about 0.9 in common with crack growth and it is independent of stress level and temperatures. 5) The equi-crack length curve is parallel to S-N$_{f}$ curve at elevated temperatures.s.s.s.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.10
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• pp.919-926
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• 2013

Experiments were conducted to determine the operating characteristics of a small-scale ORC (organic Rankine cycle) system for various low-temperature heat sources. A small-scale ORC power generation system adopting R-245fa as a working fluid was designed and manufactured. Hot water was used as the heat source, and the temperature was controlled using 110-kW electric resistance heaters that provided temperatures of up to $150^{\circ}C$. An open-drive oil-free scroll expander directly connected to a synchronous generator was installed in the ORC unit. Experiments were conducted by varying the rotational speed of the expander under the same heat source temperature conditions. The factors that influence the performance of the small-scale ORC system were analyzed and discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.926-935
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• 2015

The efficiency of genome-wide association analysis (GWAS) depends on power of detection for quantitative trait loci (QTL) and precision for QTL mapping. In this study, three different strategies for GWAS were applied to detect QTL for carcass quality traits in the Korean cattle, Hanwoo; a linkage disequilibrium single locus regression method (LDRM), a combined linkage and linkage disequilibrium analysis (LDLA) and a $BayesC{\pi}$ approach. The phenotypes of 486 steers were collected for weaning weight (WWT), yearling weight (YWT), carcass weight (CWT), backfat thickness (BFT), longissimus dorsi muscle area, and marbling score (Marb). Also the genotype data for the steers and their sires were scored with the Illumina bovine 50K single nucleotide polymorphism (SNP) chips. For the two former GWAS methods, threshold values were set at false discovery rate <0.01 on a chromosome-wide level, while a cut-off threshold value was set in the latter model, such that the top five windows, each of which comprised 10 adjacent SNPs, were chosen with significant variation for the phenotype. Four major additive QTL from these three methods had high concordance found in 64.1 to 64.9Mb for Bos taurus autosome (BTA) 7 for WWT, 24.3 to 25.4Mb for BTA14 for CWT, 0.5 to 1.5Mb for BTA6 for BFT and 26.3 to 33.4Mb for BTA29 for BFT. Several candidate genes (i.e. glutamate receptor, ionotropic, ampa 1 [GRIA1], family with sequence similarity 110, member B [FAM110B], and thymocyte selection-associated high mobility group box [TOX]) may be identified close to these QTL. Our result suggests that the use of different linkage disequilibrium mapping approaches can provide more reliable chromosome regions to further pinpoint DNA makers or causative genes in these regions.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.1
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• pp.79-86
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• 2014

Hydroxycinnamic acids have been reported to possess numerous pharmacological activities such as antioxidant, anti-inflammatory, and anti-tumor properties. However, the biological activity of 1-p-coumaroyl ${\beta}$-D-glucoside (CG), a glucose ester derivative of p-coumaric acid, has not been clearly examined. The objective of this study is to elucidate the anti-inflammatory action of CG in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. In the present study, CG significantly suppressed LPS-induced excessive production of pro-inflammatory mediators such as nitric oxide (NO) and $PGE_2$ and the protein expression of iNOS and COX-2. CG also inhibited LPS-induced secretion of pro-inflammatory cytokines, IL-$1{\beta}$ and TNF-${\alpha}$. In addition, CG significantly suppressed LPS-induced degradation of $I{\kappa}B$. To elucidate the underlying mechanism by which CG exerts its anti-inflammatory action, involvement of various signaling pathways were examined. CG exhibited significantly increased Akt phosphorylation in a concentration-dependent manner, although MAPKs such as Erk, JNK, and p38 appeared not to be involved. Furthermore, inhibition of Akt/PI3K signaling pathway with wortmannin significantly, albeit not completely, abolished CG-induced Akt phosphorylation and anti-inflammatory actions. Taken together, the present study demonstrates that Akt signaling pathway might play a major role in CG-mediated anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.4 s.247
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• pp.298-305
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• 2006

The flow around a circular cylinder which oscillates rotationally with a relatively high forcing frequency has been investigated experimentally using flow visualization and hot-wire measurements. Dominant parameters are Reynolds number (Re), oscillation amplitude $({\theta}_A)$, and frequency ratio $F_R=f_f/f_n$, where $f_f$ is the forcing frequency and $f_n$ is the natural frequency of vortex shedding. Experiments were carried out under the conditions of $Re=4.14{\times}10^3,\;{\theta}_A={\pi}/6$, and $0{\leq}F_R{\leq}2$. The effect of frequency ratio $F_R$ on the flow structure of wake was evaluated by measuring wake velocity profile and spectral analysis of hot-wire signal. Depending on the frequency ratio $F_R$, the cylinder wake has 5 different flow regimes. The vortex formation length and vortex shedding frequency are changed significantly before and after the lock-on regime. The drag coefficient was reduced under the condition of $F_R<1.0$ and the maximum drag reduction is about 33% at $F_R=0.8$. However, the drag is increased as $F_R$ increases beyond $F_R=1.0$. This active flow control method can be effective in aerodynamic applications, if the forcing parameters are selected optimally.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.523-531
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• 2012

The performance simulation of a desiccant rotor, which is a core component of a desiccant cooling system, was conducted on the basis of a theoretical solution of the heat and mass transfer process in the rotor. The simulation model was validated by comparing simulation results with experimental data; reasonable agreement was observed. The effect of the rotation speed on the performance of the desiccant rotor was investigated for various operation conditions: temperature (50 to $70^{\circ}C$), humidity ratio (0.01 to 0.02 kg/kg DA), and flow rate of regeneration air. The optimum rotation speed was determined from the maximum moisture removal capacity (MRC) of the desiccant rotor, and it was found to vary with the operation conditions. Further, the correlation for the optimum rotation speed was determined by regression analysis.