• 폴리머
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• 제32권4호
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• pp.334-339
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• 2008

최근 전기방사공정은 다양한 고분자의 마이크로 및 나노 크기 섬유를 만드는 기술로서 널리 사용되어 왔다. 일반적으로 많은 연구자들에 의하면, 다중노즐 전기방사공정은 노즐들 사이의 전기장 간섭효과 때문에 짧은 시간에 높은 생산성을 갖기 어려웠다. 이러한 문제를 극복하기 위하여 본 연구에서는 다양한 보조전극을 이용한 다중노즐 전기방사공정을 개발하였다. 본 연구에서 사용된 물질은 바이오소재로서 많이 사용되고 있는 poly($\varepsilon$-carprolactone)(PCL)을 사용하였다. 다중노즐 시스템의 영향을 확인하기 위하여 전기방사의 안정성, 다중노즐을 사용하였을 때의 생산성 및 제조된 나노섬유의 크기와 안정성을 보조전극을 사용하였을 때와 사용하지 않았을 때를 비교하였다. 결과적으로 보조전극을 사용한 노즐의 안정성이 사용하지 않은 노즐에 비해 전기방사 안정성과 우수한 생산성을 보였다.

• Journal of Ginseng Research
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• 제43권1호
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• pp.154-160
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• 2019

Background: Compound K (CK) is an active metabolite of ginseng saponin, ginsenoside Rb1, that has been shown to have ameliorative properties in various diseases. However, its role in inflammation and the underlying mechanisms are poorly understood. In this report, the antiinflammatory role of CK was investigated in macrophage-like cells. Methods: The CK-mediated antiinflammatory mechanism was explored in RAW264.7 and HEK293 cells that were activated by lipopolysaccharide (LPS) or exhibited overexpression of known activation proteins. The mRNA levels of inflammatory genes and the activation levels of target proteins were identified by quantitative and semiquantitative reverse transcription polymerase chain reaction and Western blot analysis. Results: CK significantly inhibited the mRNA expression of inducible nitric oxide synthase and tumor necrosis factor-${\alpha}$ and morphological changes in LPS-activated RAW264.7 cells under noncytotoxic concentrations. CK downregulated the phosphorylation of AKT1, but not AKT2, in LPS-activated RAW264.7 cells. Similarly, CK reduced the AKT1 overexpression-induced expression of aldehyde oxidase 1, interleukin-$1{\beta}$, interferon-${\beta}$, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. Conclusion: Our results suggest that CK plays an antiinflammatory role during macrophage-mediated inflammatory actions by specifically targeting the AKT1-mediated signaling pathway.

• 접착 및 계면
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• 제24권3호
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• pp.105-111
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• 2023

최근 귀금속 산업을 포함한 다양한 산업 분야에 있어, 생물 부착 억제를 위한 코팅 방법에 대한 관심이 증가하고 있다. 특히, 패션 주얼리와 같이 피부에 밀착하여 접촉하는 악세사리나 귀걸이, 그리고 피어싱의 경우, 금속 표면의 오염으로 인하여 접촉 부위를 자극하거나 이상 반응을 유도할 수 있다. 이에 본 연구에서는 폴리에틸렌글라이콜 양 말단에 홍합의 접착 물질로 보고된 카테콜기를 도입하여 접착성 폴리에틸렌글라이콜을 합성하고, 이를 구리와 아연의 합금인 황동 표면에 코팅하여 생물 부착 억제 효과를 관찰하였다. 접착성 폴리에틸렌글라이콜이 코팅된 황동 표면은 우수한 세포 생존율을 나타낼 뿐 아니라, 단백질이나 세포의 부착을 억제하는 효과를 나타냈다. 그러므로 귀금속 산업 분야에 있어서 접착성 폴리에틸렌글라이콜을 이용한 다양한 응용이 기대된다.

• Journal of Ginseng Research
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• 제44권4호
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• pp.655-663
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• 2020

Background: Korean Red Ginseng is known to exhibit immune-enhancing and anti-inflammatory properties. The immune-enhancing effects of the nonsaponin fraction (NSF) of Korean Red Ginseng have been studied in many reports. However, the gastroprotective effect of this fraction is not fully understood. In this study, we demonstrate the activities of NSF for gastrointestinal protection and its related critical factor. Methods: The in vitro and in vivo regulatory functions of NSF on cyclooxygenase-1 (COX-1) messenger RNA and protein levels were examined by reverse transcription polymerase chain reaction and immunoblotting analyses. Gastroprotective effects of NSF were investigated by histological score, gastric juice pH, and myeloperoxidase activity on indomethacin-induced, cold stress-induced, and acetylsalicylic acid-induced gastritis and dextran sulfate sodium-induced colitis in in vivo mouse models. Results: NSF did not show cytotoxicity, and it increased COX-1 messenger RNA expression and protein levels in RAW264.7 cells. This upregulation was also observed in colitis and gastritis in vivo models. In addition, NSF treatment in mice ameliorated the symptoms of gastrointestinal inflammation, including histological score, colon length, gastric juice pH, gastric wall thickness, and myeloperoxidase activity. Conclusion: These results suggest that NSF has gastroprotective effects on gastritis and colitis in in vivo mouse models through COX-1 upregulation.

• 전자공학회논문지CI
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• 제47권3호
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• pp.67-75
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• 2010

본 논문에서는 성능향상을 위하여 개체속력 개념을 적용한 박테리아 협동 최적화 방법을 제안한다. 기존의 박테리아 협동 최적화 방법에서는 개체별로 속력이 일정해 모든 개체가 같은 시간에 똑 같은 거리를 움직인다. 이러한 방법은 개체의 적합도가 좋은 개체나 나쁜 개체가 같은 속력으로 움직임으로서 효과적으로 최적 해를 찾아가지 못하는 문제점이 있었다. 이러한 문제점을 개선하고자 개체의 적합도를 이용하여 개체별 등급을 매기고 등급에 따라서 한 번에 이동할 수 있는 거리를 다르게 하는 속력 개념을 적용하였다. 즉 적합도가 낮은 개체는 적합도가 높은 영역으로 빨리 이동하기위하여 속력을 높이고 적합도가 높은 개체는 주변에 최적 해가 있을 가능성이 있으므로 속력을 낮게 유지하였다. 4개의 함수 최적화 문제에 적용해본 결과 속력개념을 적용하지 않은 방법에 대하여 상당한 성능향상이 있음을 보았다. 특히 성능향상을 위하여 기존에 도입했던 등급별 교체방법보다도 더 좋은 성능을 보였다. 이는 박테리아 협동 최적화의 성능을 향상시키기 위한 방법으로 속력개념을 적용하는 것이 매우 유용함을 보여준다.

• Journal of Ginseng Research
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• 제45권2호
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• pp.354-360
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• 2021

Background: Protopanaxatriol (PPT) is a secondary intestinal metabolite of ginsenoside in ginseng. Although the effects of PPT have been reported in various diseases including cancer, diabetes and inflammatory diseases, the skin protective effects of PPT are poorly understood. Methods: HaCaT cells were treated with PPT in a dose-dependent manner. mRNA and protein levels which related to skin barrier and hydration were detected compared with retinol. Luciferase assay was performed to explore the relative signaling pathway. Western blot was conducted to confirm these pathways and excavated further signals. Results: PPT enhanced the expression of filaggrin (FLG), transglutaminase (TGM)-1, claudin, occludin and hyaluronic acid synthase (HAS) -1, -2 and -3. The mRNA expression levels of FLG, TGM-1, HAS-1 and HAS-2 were suppressed under NF-κB inhibition. PPT significantly augmented NF-κB-luc activity and upregulated Src/AKT/NF-κB signaling. In addition, PPT also increased phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK and p38 and upstream MAPK activators (MEK and MKK). Furthermore, transcriptional activity of AP-1 and CREB, which are downstream signaling targets of MAPK, was enhanced by PPT. Conclusion: PPT improves skin barrier function and hydration through Src/AKT/NF-κB and MAPK signaling. Therefore, PPT may be a valuable component for cosmetics or treating skin disorders.

• 한국항공우주학회지
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• 제46권9호
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• pp.712-722
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• 2018

본 논문에서는 곤충 모방 날갯짓 비행체의 가장 중요한 설계 변수 중 하나인 날개에 대한 파라메트릭 연구에 대해 서술하였다. 추력, 피칭모멘트, 소비전력, 추력 대 전력비의 비교 및 분석을 통해 날개 형상에 대한 실험적 연구를 진행하였다. 힘과 모멘트는 2축 밸런스를 이용하여 측정되었으며 날갯짓 주파수는 홀센서를 이용하여 측정되었다. 날개 형태는 겹 날개 형태를 채택하였으며 이를 통해 Clap and fling 효과를 구현하였다. 기준 날개 형상으로 잠자리의 날개를 선정하였고, 이를 기준으로 가로세로비 및 면적에 대한 실험을 진행하였다. 결과적으로, 가로세로비와 면적이 증가할수록 추력, 피칭모멘트, 소비전력이 증가하는 것을 확인하였다. 또한, 일정 수준 이상의 가로세로비 혹은 면적을 가지는 날개를 메커니즘에 적용하였을 때 메커니즘이 정상적으로 구동되지 않는 것을 확인하였다. 최종적으로 날개 형상 선정은 필요한 최소추력을 만족시키는 날개 중에서 추력 대 전력비를 비교함으로써 이루어졌다. 하지만 추력선과 무게중심의 불일치로 인한 모멘트의 발생으로 안정성을 확보할 수 없었다. 이에 안정성을 확보하기 위해 상단과 하단에 댐퍼를 부착한 실내 비행 시험을 통해 날개의 파라메트릭 연구 결과에 대한 간접적인 성능 검증을 수행하였다.

• Journal of Ginseng Research
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• 제41권1호
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• pp.43-51
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• 2017

Background: BIOGF1K, a compound K-rich fraction prepared from the root of Panax ginseng, is widely used for cosmetic purposes in Korea. We investigated the functional mechanisms of the anti-inflammatory and antioxidative activities of BIOGF1K by discovering target enzymes through various molecular studies. Methods: We explored the inhibitory mechanisms of BIOGF1K using lipopolysaccharide-mediated inflammatory responses, reporter gene assays involving overexpression of toll-like receptor adaptor molecules, and immunoblotting analysis. We used the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to measure the antioxidative activity. We cotransfected adaptor molecules, including the myeloid differentiation primary response gene 88 (MyD88) and Toll/interleukin-receptor domain containing adaptor molecule-inducing interferon-${\beta}$ (TRIF), to measure the activation of nuclear factor (NF)-${\kappa}B$ and interferon regulatory factor 3 (IRF3). Results: BIOGF1K suppressed lipopolysaccharide-triggered NO release in macrophages as well as DPPH-induced electron-donating activity. It also blocked lipopolysaccharide-induced mRNA levels of interferon-${\beta}$ and inducible nitric oxide synthase. Moreover, BIOGF1K diminished the translocation and activation of IRF3 and NF-${\kappa}B$ (p50 and p65). This extract inhibited the upregulation of NF-${\kappa}B$-linked luciferase activity provoked by phorbal-12-myristate-13 acetate as well as MyD88, TRIF, and inhibitor of ${\kappa}B$ ($I{\kappa}B{\alpha}$) kinase ($IKK{\beta}$), and IRF3-mediated luciferase activity induced by TRIF and TANK-binding kinase 1 (TBK1). Finally, BIOGF1K downregulated the NF-${\kappa}B$ pathway by blocking $IKK{\beta}$ and the IRF3 pathway by inhibiting TBK1, according to reporter gene assays, immunoblotting analysis, and an AKT/$IKK{\beta}$/TBK1 overexpression strategy. Conclusion: Overall, our data suggest that the suppression of $IKK{\beta}$ and TBK1, which mediate transcriptional regulation of NF-${\kappa}B$ and IRF3, respectively, may contribute to the broad-spectrum inhibitory activity of BIOGF1K.

• Journal of Ginseng Research
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• 제42권3호
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• pp.389-399
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• 2018

Background: The antioxidant effects of Panax ginseng have been reported in several articles; however, little is known about the antimelanogenesis effect, skin-protective effect, and cellular mechanism of Panax ginseng, especially of P. ginseng calyx. To understand how an ethanol extract of P. ginseng berry calyx (Pg-C-EE) exerts skin-protective effects, we studied its activities in activated melanocytes and reactive oxygen species (ROS)-induced keratinocytes. Methods: To confirm the antimelanogenesis effect of Pg-C-EE, we analyzed melanin synthesis and secretion and messenger RNA and protein expression levels of related genes. Ultraviolet B (UVB) and hydrogen peroxide ($H_2O_2$) were used to induce cell damage by ROS generation. To examine whether this damage is inhibited by Pg-C-EE, we performed cell viability assays and gene expression and transcriptional activation analyses. Results: Pg-C-EE inhibited melanin synthesis and secretion by blocking activator protein 1 regulatory enzymes such as p38, extracellular signal-regulated kinases (ERKs), and cyclic adenosine mono-phosphate response element-binding protein. Pg-C-EE also suppressed ROS generation induced by $H_2O_2$ and UVB. Treatment with Pg-C-EE decreased the expression of matrix metalloproteinases, mitogen-activated protein kinases, and hyaluronidases and increased the cell survival rate. Conclusion: These results suggest that Pg-C-EE may have antimelanogenesis properties and skin-protective properties through regulation of activator protein 1 and cyclic adenosine monophosphate response element-binding protein signaling. Pg-C-EE may be used as a skin-improving agent, with moisture retention and whitening effects.