• Archives of Pharmacal Research
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• v.28 no.8
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• pp.948-955
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• 2005

Glomerular mesangial cells (GMCs) in diverse renal diseases undergo cell proliferation and/or hypertrophy, and gangliosides have been reported to play an important role in modulating cell structure and function. This study compared the effects of transforming growth $factor-\beta\; (TGF­\beta1)$ and the effects of the application of exogenous gangliosides on GMCs and investigated whether the application of exogenous gangliosides regulated cellular proliferation and hypertrophy. Human GMCs were cultured with exogenous gangliosides and $TGF-\beta1$ in a media containing $10\%$ fetal bovine serum and in a media without the fetal bovine serum. Exogenous gangliosides biphasically changed the proliferation of human GMCs (0.1-1.0 mg/mL). A low concentration (0.1 mg/mL) of gangliosides mainly increased the number of human GMCs, whereas cellular proliferation was significantly reduced by raising the concentration of exogenous gangliosides. $TGF-\beta1$ greatly reduced the number of human GMCs in a concentration­dependent manner (1-10 ng/mL). Serum deprivation accelerated the gangliosides- and $TGF­\beta1-induced$ inhibition of mesangial cell proliferation to a greater extent. Gangliosides (1.0 mg/ mL) and $TGF-\beta1$ (10 ng/mL) both caused a significant increase in the incorporation of $[^3H]leucine$ per cell in the serum-deprived condition, whereas it was completely reversed in serum­supplemented condition. Similar results to the $[^3H]leucine$ incorporation were also observed in the changes in cell size measured by flow cytometric analysis. These results show that exogenous gangliosides modulate cell proliferation and hypertrophy in cultured human GMCs, and these cellular responses were regulated differently based on whether the media contained serum or not. Results from the present study raise new possibilities about the potential involvement of gangliosides in the development of mesangial cell proliferation and hypertrophy.

• Journal of The Korean Association of Information Education
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• v.8 no.3
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• pp.321-332
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• 2004

Recently, learning how to learn is a matter of concern among many pedagogists and become the important subject matter of school education. That's why there are many learners who fail to get good results compared with their potential abilities and efforts, as well as the necessity to educate independent and self-determined learner by teaching learning strategies that can help leaners to get new information and skills by themselves in an information-oriented society was emphasized. Therefore, this study is to utilize the learning strategy in order to improve the learners study skills, and grope for the method of self-directed learning about the social studies centered on the learners. And, it is to utilize the reciprocal teaching with the learning strategy for improving the learners study skills. Also, it is to make the learners induced to participate in the teaching for social studies actively, grafting the characteristics of web on the reciprocal teaching. According to this intent, this study was developed as three steps. As for the first step, it investigated the reciprocal teaching, a teaching-learning theory to apply to the program, and the theoretical background about web utility in the social studies. On the second step, it embodied the reciprocal teaching-learning system about the we-based social studies that will be available in the self-directed learning centered on the learners. Lastly, it analysed the change of recognition about the learners social study skills and the learning the social studies after applying the materialized website to the actual lesson.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.295-307
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• 2006

Styela clava, called non-native tunicate or sea squirt, is habitat which include bays and harbors in Korea and several sites in the sea faced world. We fabricate cellulose membrane nerve conduit (CMNC) from this native sea squirt skin, and evaluate the capacity of promoting peripheral nerve regeneration in the rat sciatic nerve defect model. After processing the pure cellulose membrane from the sea squirt skin as we already published before, CMNC was designed as a non-tubular sheet with 14 mm length and 4 mm width. Total eleven male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into sham group (n=2), silicone tube grafted control group (n=3) and experimental group (n=6). Each CMNC grafted nerve was evaluated after 4, 8 and 12 weeks in the experimental group, and after 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were all examined using image analyzer and electromicroscopic methods in the all groups. The regenerated axon and nerve sheath were found only in the inner surface of the CMNC after 4 weeks and became more thicker after 8 and 12 weeks. In the TEM study, CMNC grafted group showed more abundant organized myelinated nerve fibers with thickened extracellular matrix than silicone conduit grafted group after 12 weeks. The sciatic function index (SFI) and ankle stance angle (ASA) in the functional evaluation were $-47.2{\pm}3.9$, $35.5^{\circ}{\pm}4.9^{\circ}$ in CMNC grafted group (n=2) and $-80.4{\pm}7.4$, $29.2^{\circ}{\pm}5.3^{\circ}$ in silicone conduit grafted group (n=3), respectively. And the myelinated axon was 41.59% in CMNC group and 9.51% in silicone conduit group to the sham group. The development of a bioactive CMNC to replace autogenous nerve grafts offers a potential and available approach to improved peripheral nerve regeneration. As we already published before, small peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx, induced the effective axonal regeneration with rapid growth of Schwann cells beneath the inner surface of CMNC. So the possibilities of clinical application as a peripheral nerve regeneration will be able to be suggested.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.4
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• pp.177-190
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• 2016

In case of the seabed around and under gravity structures such as submerged breakwater is exposed to a large wave action long period, the excess pore pressure will be generated significantly due to pore volume change associated with rearrangement soil grains. This effect will lead a seabed liquefaction around and under structures as a result from decrease in the effective stress. Under the seabed liquefaction occurred and developed, the possibility of structure failure will be increased eventually. Lee et al.(2016) studied for regular waves, and this study considered for irregular waves with the same numerical analysis method used for regular waves. Under the condition of the irregular wave field, the time and spatial series of the deformation of submerged breakwater, the pore water pressure (oscillatory and residual components) and pore water pressure ratio in the seabed were estimated and their results were compared with those of the regular wave field to evaluate the liquefaction potential on the seabed quantitatively. Although present results are based on a limited number of numerical simulations, one of the study's most important findings is that a more safe design can be obtainable when analyzing case with a regular wave condition corresponding to a significant wave of irregular wave.

• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.459-470
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• 2020

This study investigated the effects of the proteolytic hydrolysates of α-lactalbumin (LA), β-lactoglobulin (LG) and bovine serum albumin (BSA) by alcalase on inflammatory cytokines. The proteolytic hydrolysates were separated into two fraction of peptides, ≤ 10,000 Da and > 10,000 Da, respectively, because various low molecular weight peptides were generated during the hydrolysis reaction time. Among the hydrolysate peptides, BSA (all types), β-LG (> 10,000 Da), and α-LA (> 10,000 Da) showed an inhibitory activity against thymic stromal lymphopoietin (TSLP) mRNA expression in lipopolysaccharide-induced RAW264.7 murine macrophages. α-LA (> 10,000 Da), β-LG (hydrolysates), and BSA (> 10,000 Da) showed an inhibitory activity against tumor necrosis factor (TNF)-α expression. α-LA (all types), β-LG (hydrolysates, > 10,000 Da), and BSA (> 10,000 Da) showed an inhibitory activity against interleukin-6 (IL-6) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against inducible nitric oxide synthase (iNOS) expression. α-LA (> 10,000 Da), β-LG (> 10,000 Da), and BSA (all types) showed an inhibitory activity against cyclooxygenase (COX)-2 expression. The lowest level of TNF-α production was measured with α-LA (> 10,000 Da) and β-LG (> 10,000 Da) for all types, and a similar low level was measured for all types of BSA. The highest level of IL- 6 production was measured with α-LA (≤ 10,000 Da) among α-LA, β-LG, and IL-6. The low level of NO production was similar with α-LA, β-LG, and BSA but not with α-LA (≤ 10,000 Da). These potential peptides from whey protein hydrolysates could be used for food, medicinal, and industrial applications.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.2
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• pp.114-121
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• 2020

Objective: Despite extensive research on implantation failure, little is known about the molecular mechanisms underlying the crosstalk between the embryo and the maternal endometrium, which is critical for successful pregnancy. Profilin 1 (PFN1), which is expressed both in the embryo and in the endometrial epithelium, acts as a potent regulator of actin polymerization and the cytoskeletal network. In this study, we identified the specific role of endometrial PFN1 during embryo implantation. Methods: Morphological alterations depending on the status of PFN1 expression were assessed in PFN1-depleted or control cells grown on Matrigel-coated cover glass. Day-5 mouse embryos were cocultured with Ishikawa cells. Comparisons of the rates of F-actin formation and embryo attachment were performed by measuring the stability of the attached embryo onto PFN1-depleted or control cells. Results: Depletion of PFN1 in endometrial epithelial cells induced a significant reduction in cell-cell adhesion displaying less formation of colonies and a more circular cell shape. Mouse embryos co-cultured with PFN1-depleted cells failed to form actin cytoskeletal networks, whereas more F-actin formation in the direction of surrounding PFN1-intact endometrial epithelial cells was detected. Furthermore, significantly lower embryo attachment stability was observed in PFN1-depleted cells than in control cells. This may have been due to reduced endometrial receptivity caused by impaired actin cytoskeletal networks associated with PFN1 deficiency. Conclusion: These observations definitively demonstrate an important role of PFN1 in mediating cell-cell adhesion during the initial stage of embryo implantation and suggest a potential therapeutic target or novel biomarker for patients suffering from implantation failure.

• Nuclear Engineering and Technology
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• v.47 no.6
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• pp.678-699
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• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.411-418
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• 2017

Background: Recently, protein from ginseng was studied and used for the treatment of several kinds of diseases. However, the effect of ginseng total protein (GTP) on proliferation and wound healing in fibroblast cells remains unclear. Methods: In this study, cell viability was analyzed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Cell cycle distribution was analyzed by flow cytometer. The levels of transforming growth factor ${\beta}1$, vascular endothelial growth factor, and collagens were analyzed by enzyme-linked immunosorbent assay and immunofluorescence staining. The expressions of cyclin A, phosphorylation of extracellular signal-related kinase (p-ERK1/2), and ERK1/2 were analyzed by Western blotting. Results: Our results showed that GTP promoted cell proliferation and increased the percentage of cells in S phase through the upregulation of cyclin A in NIH/3T3 cells. We also found that GTP induced the secretion of type I collagen, and promoted the expression of other factors that regulate the synthesis of collagen such as transforming growth factor ${\beta}1$ and vascular endothelial growth factor. In addition, the phosphorylation of ERK1/2 at Thr202/Tyr204 was also increased by GTP. Conclusion: Our studies suggest that GTP promoted proliferation and secretion of collagen in NIH/3T3 cells by activating the ERK signal pathway, which shed light on a potential function of GTP in promoting wound healing.

• Journal of Ginseng Research
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• v.44 no.2
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• pp.291-299
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• 2020

Background: Ginseng (G) and Ligustrum lucidum Ait (LLA) are core traditional Chinese medicines in treating myelosuppression formula. The present study was designed to profile effect of G and LLA herb pair (G-LLA) on myelosuppressed mice. Methods: The mice myelosuppression model was established by intraperitoneal (i.p.) injection of cyclophosphamide (Cy). Hematopoietic function of bone marrow was measured by hemopoietic progenitor cell culture and peripheral blood count, and serum hemopoietic factors were tested by enzyme-linked immunosorbent assay. Bone marrow cell cycle was performed by flow cytometry. HPLC was used to measure 20 potential chemical components related to myelosuppression, including ginsenoside Rg₁, Re, Rb₁, Rc, Rb₂, Rb₃, Rd, Rk₃, Rh₄, 20 (S)-Rg₃, 20 (R)-Rg₃, Rk₁, Rg₅, salidroside, and so on. Results: G, LLA, and G-LLA improved the amount of peripheral blood cells and bone marrow cells of myelosuppressed mice (P < 0.01). They significantly increased the colony quantity of colony-forming unit-granulocyte macrophage, burst-forming unit-erythroid, colony-forming unit-erythroid, and colony-forming unit-megakaryocyte and amount of G₂/M and S phase cells (P < 0.01). They also significantly decreased the amount of hematopoiesis-related cytokines (P < 0.01). The content of chemical components in G-LLA changed, and the change of rare saponin was the most obvious. Conclusion: These results show that G-LLA herb pair might produce synergistic or complementary compatibility effects on bone marrow suppression after chemotherapy. It suggests that the substance basis of G-LLA for treating bone marrow suppression may be effective chemical components.

• Food Science and Preservation
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• v.23 no.7
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• pp.1026-1032
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• 2016

Citrus platymamma hort. ex Tanaka is widely used in traditional Korean medicine because of its medicinal benefits including an anti-inflammatory effect. This study aimed to evaluate changes in the flavonoid content and anti-inflammatory activities of C. platymamma during its harvest period. Fruit peel samples were obtained between September 2015 and February 2016. The results indicate that C. platymamma peel extract (CPE) was an effective inhibitor of lipopolysaccharide (LPS)-induced NO production in RAW264.7 cells. The inhibitory effects of CPE at $100{\mu}g/mL$ concentration included dose-dependent decreases in the expression of iNOS and COX-2 proteins. In addition, CPE decreased the expression of pro-inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, and IL-6. The highest anti-inflammatory activity and flavonoid content were observed in CPE of C. platymamma peel harvested during the immature fruit period in September. Further, to assess the suitability of CPE for cosmetic use, we performed MTT assays using HaCaT keratinocytes and observed that CPE did not exhibit any cytotoxicity. To test the potential application of CPE as a cosmetic material, we also performed primary skin irritation tests on normal skin of 30 volunteers and no adverse reactions were observed. The results of this study indicate that CPE may be considered as an anti-inflammatory candidate for inclusion in cosmetic materials.