• BMB Reports
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• 제52권8호
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• pp.514-519
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• 2019

Osteoclasts are multinucleated giant cells derived from myeloid progenitors. Excessive bone resorption by osteoclasts can result in serious clinical outcomes for which better treatment options are needed. Here, we identified fibronectin leucine-rich transmembrane protein 2 (Flrt2), a ligand of the Unc5 receptor family for neurons, as a novel target associated with the late/maturation stage of osteoclast differentiation. Flrt2 expression is induced by stimulation with receptor activator of nuclear factor-kB ligand (RANKL). Flrt2 deficiency in osteoclasts results in reduced hyper-multinucleation, which could be restored by RNAi-mediated knockdown of Unc5b. Treatment with Netrin1, another ligand of Unc5b which negatively controls osteoclast multinucleation through down regulation of RANKL-induced Rac1 activation, showed no inhibitory effects on Flrt2-deficient cells. In addition, RANKL-induced Rac1 activation was attenuated in Flrt2-deficient cells. Taken together, these results suggest that Flrt2 regulates osteoclast multinucleation by interfering with Netrin 1-Unc5b interaction and may be a suitable therapeutic target for diseases associated with bone remodeling.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.165.2-165.2
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• 2003

Phosphatidylinositol 3-kinase (PI3K) and Rac play important roles that regulate cellular functions including cell survival and migration. In the present study, we investigated the functional roles of PI3K and Rac1 pathways in H-ras-induced invasive phenotype and motility of MCF10A cells. Akt, a downstream molecule of PI3K, was effectively activated not only by H-ras but also by N-ras, suggesting that the activation of PI3K pathway is not sufficient to induce metastatic potential of MCF10A cells. (omitted)

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2299-2303
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• 2014

Two diastereoisomers of cyclo(Pro-Tyr) have been synthesized simultaneously. The crystal structures and conformations of both cyclo($\small{L}$-Pro-$\small{L}$-Tyr) and a racemic mixture of cyclo($\small{D}$-Pro-$\small{L}$-Tyr) and cyclo($\small{L}$-Pro-$\small{D}$-Tyr), abbreviated as rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr), have been determined by a single-crystal X-ray diffraction study at low temperature. The crystals of rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr) belong to orthorhombic space group $Pna2_1$ with a = 10.755 (1), b = 12.699 (1), c = 9.600 (1) ${\AA}$ and Z = 4. The tyrosine side chain is folded towards the diketopiperazine (DKP) ring. The DKP ring adopts a twist boat conformation with pseudo symmetry $C_{2v}$. The pyrrolidine ring has an envelope conformation with the N5, C4, C7 and C8 atoms in a plane. The crystal of rac-cyclo($\small{D}$-Pro-$\small{L}$-Tyr/$\small{L}$-Pro-$\small{D}$-Tyr) is stabilized by hydrogen bonds between amide N2-H2 and carbonyl oxygen O2 in the neighbor. The hydroxyl group of tyrosine residue is also hydrogen bonded to the oxygen of the carbonyl group of the DKP ring in the next molecule. The spectroscopic properties of both isomers are also described.

• 동력기계공학회지
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• 제17권3호
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• pp.35-43
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• 2013

Generally, the chassis of an indoor RAC is composed of a rear-guider and a stabilizer. The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of the chassis of an indoor RAC. The purpose of this paper is to select the optimum design factors through the aerodynamic performance of a cross-flow fan. The design factors are the leading angle of a rear-guider (${\theta}_1$), a stabilizer setup angle(${\theta}_2$), a rear-guider clearance(${\epsilon}_1$), and a stabilizer clearance(${\epsilon}_2$), respectively. As a result, the optimum design factors of an indoor RAC can be presented as a combination of ${\theta}_1=33^{\circ}$, ${\theta}_2=55^{\circ}$, ${\epsilon}_1=6{\sim}8mm$, and ${\epsilon}_2=7mm$ through the analysis of a static pressure coefficient and a static pressure efficiency.

• 농업과학연구
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• 제47권4호
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• pp.707-715
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• 2020

An experiment was designed to assess ractopamine supplementation on growth, meat quality and carcass, and fecal scores of pigs. The 96 crossbred pigs ([Yorkshire× Landrace] × Duroc) had an average body weight of 72.8 ± 2.5 kg. Randomized allocation was followed in the allotment of the pigs according to their body weight into 1 of 2 dietary treatments: 1) CON, basal diet and 2) RAC (ractopamine hydrochloride), CON + 1% ractopamine with 12 replication pens per treatment including equal numbers of barrows (2) and gilts (2) per pen. At the end of the experiment, the lean meat percentage was higher (p < 0.05) for the RAC group compared to the CON group. Dietary ractopamine supplementation did not influence (p > 0.05) the growth performance and fecal score throughout the experimental period. In regard to sensory evaluation, higher (p < 0.05) scores for color and firmness were observed in the RAC group than in the CON group. Drip loss (p < 0.05) was higher in the ractopamine fed diet group compared to the control diet group at day 1. Additionally, longissimus muscle was improved (p < 0.05) in the ractopamine treated diet group than in the control diet group. In conclusion, in the early stage, ractopamine supplementation may not influence the growth performance, but it improves the leanness in the meat of finishing pigs.

• International Journal of Oral Biology
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• 제41권4호
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• pp.231-236
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• 2016

Inhibition of Rho-associated coiled coil-containing kinase (ROCK) has been reported to promote differentiation of neuronal cells. Here, we examined the effect of Y-27632, a ROCK inhibitor, on the outgrowth of neurites in PC12 cells. Y-27632 caused a rapid induction of neurite outgrowth in PC12 cells in a time-dependent manner. The neurite outgrowth, triggered by Y-27632, was accompanied by Rac1 activation, and was attenuated by Rac1 inhibitor NSC23766, in a concentration-dependent manner. Y-27632 also induced an increase in the production of reactive oxygen species (ROS). Pretreatment with N-acetylcysteine, an ROS scavenger, inhibited the ROS generation and neurite outgrowth in response to Y-27632. These results indicate that the activation of Rac1 and the generation of ROS contribute to the neurite outgrowth triggered by Y-27632 in PC12 cells.

• BMB Reports
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• 제51권5호
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• pp.230-235
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• 2018

Bone resorption by multinucleated osteoclasts is a multistep process involving adhesion to the bone matrix, migration to resorption sites, and formation of sealing zones and ruffled borders. Macrophage colony-stimulating factor (M-CSF) and osteopontin (OPN) have been shown to be involved in the bone resorption process by respective activation of integrin ${\alpha}v{\beta}3$ via "inside-out" and "outside-in" signaling. In this study, we investigated the link between signal modulators known to M-CSF- and OPN-induced osteoclast adhesion and spreading. M-CSF- and OPN-induced osteoclast adhesion was achieved via activation of stepwise signals, including integrin ${\alpha}v{\beta}3$, $PLC{\gamma}$, $PKC{\delta}$, and Rac1. Osteoclast spreading induced by M-CSF and OPN was shown to be controlled via sequential activation, consistent with the osteoclast adhesion processes. In contrast to osteoclast adhesion, osteoclast spreading induced by M-CSF and OPN was blocked via activation of $PLC{\gamma}/PKC{\alpha}/RhoA$ signaling. The combined results indicate that osteoclast adhesion and spreading are selectively regulated via $PLC{\gamma}/PKC{\alpha}-PKC{\delta}/RhoA-Rac1$ signaling.

• BMB Reports
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• 제52권8호
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• pp.490-495
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• 2019

Using tunneling nanotubes (TNTs), various pathological molecules and viruses disseminate to adjacent cells intercellularly. Here, we show that the intracellular invasion of Mycoplasma hyorhinis induces the formation of actin- and tubulin-based TNTs in various mammalian cell lines. M. hyorhinis was found in TNTs generated by M. hyorhinis infection in NIH3T3 cells. Because mycoplasma-free recipient cells received mycoplasmas from M. hyorhinis-infected donor cells in a mixed co-culture system and not a spatially separated co-culture system, direct cell-to-cell contact via TNTs was necessary for the intracellular dissemination of M. hyorhinis. The activity of Rac1, which is a small GTP binding protein, was increased by the intracellular invasion of M. hyorhinis, and its pharmacological and genetic inhibition prevented M. hyorhinis infection-induced TNT generation in NIH3T3 cells. The pharmacological and genetic inhibition of Rac1 also reduced the cell-to-cell dissemination of M. hyorhinis. Based on these data, we conclude that intracellular invasion of M. hyorhinis induces the formation of TNTs, which are used for the cell-to-cell dissemination of M. hyorhinis.

• 대한한의학회지
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• 제17권1호
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• pp.266-279
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• 1996

To complement and develop the Orient Medical Bian Zheng treatmemt(韓方辨證施治), I have observed and analysed 68 persons who have recieved medical treatment because of the epigastric pain. Considering and analysed the Clinical Diagnosis(臨床診斷) and Clinical Bian Zheng(臨床辨證), Clinical Diagnosis(臨床診斷) and Gastroscopic Bian Zheng(微觀辨證), Clinical Bian Zheng(臨床辨證) and Gastroscopic Bian Zheng(微觀辨證), case history, age and sex, I have obtained the conclusion as follows. 1. The frequency of epigastric pain according to the classfication of Clinical Bian Zheng(臨床辨證) most occured in Gi Che Zheng(氣滯證), then in Huh Han Zheng(虛寒證). and least in Wi Youl Zheng. 2. There is no clear connection between the Clinical Bian Zheng(臨床辨證) and Clinical Diagnosis(臨床診斷). 3. The frequency of the epigastric pain according to Gastroscopic Bian Zheng(微觀辨證), mainly occurred in Wi youl Type(胃熱型), Wi Rac Jac Sang Type(胃絡灼傷滯型)and then occurred in Wi Han Type(胃寒型), and least occurred in Wi Rac A Che Type(胃絡瘀滯型) 4. Having observed the relation between the Gastroscopicin Bian Zheng(微觀辨證), and Clinical Diagnosis(臨床診斷) as pathological process, I have obtained the result that Wi Youl type(胃熱型) and Wi Rac Jac Sang Type(胃絡灼傷型) mainly occurred in Erosive Gastritis and Superficial Gastritis at the early stage, and Wi Rac A Che Type(胃絡瘀滯型) occurred in the whole stage among the Wuperficial Gastritis, Atro pic Gastritis, and Erosive Gastritis, Gastric Cancer, and the Wi Han Type(胃寒型) mainly occurred in Atropic Gastritis at the later stage. 5. The relation between Clinical Bian Zheng(臨床辨證) and Gastroscopic Bian Zheng(微觀辨證) do not coincide. 6. Observing the relation between the Clinical Bian Zheng(臨床辨證) and case history, Gi Che Zheng(氣滯證), Huh Han Zheng(虛寒證), Wi Youl Zheng(胃熱證) were commonly seen in the early stage of the case history, and Eum Huh Zheng(陰虛證) and Houl A Zheng(血瘀證) were seen in every stage. 7. Observing the relation between the Clinical Bian Zheng(臨床辨證) and age, Gi Che Type(氣滯型) was mostly seen in the thirties and other Bian Zheng(辨證) was seen after the middle 8. Observing the relation between the Clinical Bian Zheng(臨床辨證) and sex, Gi Che Type(氣滯型) was seen at high ratio in both sexes. 9. Observing the relation between the Gastroscopic Bian Zheng(微觀辨證) and case history Wi Han Type(胃寒證), Wi Youl Type(胃熱型), Wi Rac Jac Sang Type(胃絡灼傷型) were seen in the early stage of the case history Wi Rac A Che Type(胃絡瘀滯型) was mostly seen in the later stage. 10. There was no clear connection between the Gastroscopic Bian Zheng(微觀辨證) and age, sex. Although the examples were not sufficient, recipe regarding the partial variation state of stomach mucos together with Orient Medical Bian Zheng(韓方辨證) treatment seems to be useful in the effective treatment of Bi wi(脾胃) disease besides the epigastric pain.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.785-792
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• 2017

최근 양질의 천연골재의 부족으로 인하여 콘크리트용 순환골재의 적용성에 대한 관심이 증가하고 있다. 그러나, 순환골재는 다량의 부착모르타르를 포함하고 있어 콘크리트의 강도감소, 내구성 저하, 균열발생의 원인이 되기도 한다. 본 연구에서는 순환 굵은골재 콘크리트의 역학적 성능 및 내구성에 대한 나일론 섬유의 영향에 대하여 실험적으로 고찰하였다. 섬유보강 순환골재 콘크리트 공시체를 제조하기 위하여 나일론 섬유를 0. 0.6 및 $1.2kg/m^3$의 3단계로 혼입하였으며, 콘크리트의 압축 및 쪼갬 인장강도, 흡수율, 투수공극량 및 총통과전하량을 측정하여 섬유보강 부순골재 콘크리트와 비교, 고찰하였다. 또, 수화생성물, 천이지대 등 미세조직구조를 관찰하기 위하여 재령 28일 콘크리트에 대하여 주사형전자현미경(SEM) 분석을 실시하였다. 본 실험에서 도출된 실험결과에 의하면, 순환골재 콘크리트는 부순골재 콘크리트에 비하여 성능이 떨어지는 것으로 나타났으나, 순환골재 콘크리트에 나일론 섬유를 혼입할 경우, 나일론 섬유의 가교작용으로 인하여 시멘트 매트릭스의 부착력을 증진시켜 콘크리트의 성능을 개선시키는 것으로 조사되었다.