• Advances in concrete construction
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• 제10권5호
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• pp.403-416
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• 2020

This study investigated the effect of alkaline activators - NaOH_aq (NH) (NH: 0-16 M) and Na₂SiO_3aq (NS) (NS/NH: 0-3.5) in the synthesis of silico-manganese fume (SMF) and ground blast furnace slag (BFS) blended alkali-activated mortar (AASB). The use of individual activator was ineffective in producing AASB of sufficient fresh and hardened properties, compared to the synergy of both activators. This may be attributed to incomplete dissolution and condensation of oligomers required for gelation of the binder. An inverse relationship was noted among the fresh properties and the NH concentration or NS/NH ratio. This was influenced by the dissolution and condensation of silicate monomers under polymerization process. The maximum 28-day strength of ~45 MPa, setting time of 60 min and flow of 182 mm was obtained with the use of combined activators (10M-NH and NS/NH=2.5). The combined activators at NS/10M-NH=2.5 constituted SiO₂/Na₂O, H₂O/Na₂O and H₂O/SiO₂ molar ratio of 1.61, 17.33 and 10.77, respectively. This facilitated the formation of C-S-H, C/K-A-S-H and C-Mn-S-H in the framework together with an increase in the crystallinity due to more silicate re-organization within the aluminosilicate chain. On comparison of the high concentrated with mild alkali synthesized product, it revealed that the concentration of OH^- and Si monomers together with alkali metals influenced the dissolution of precursors and embedment of the constituent elements in the polymeric matrix. These factors eventually contributed to the microstructural densification of the mortar prepared with NS/10M-NH=2.5 thereby enhancing the compressive strength.

• Journal of Ginseng Research
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• 제42권1호
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• pp.81-89
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• 2018

Background: BIOGF1K, a compound-K-rich fraction, has been shown to display anti-inflammatory activity. Although Panax ginseng is widely used for the prevention of photoaging events induced by UVB irradiation, the effect of BIOGF1K on photoaging has not yet been examined. In this study, we investigated the effects of BIOGF1K on UVB-induced photoaging events. Methods: We analyzed the ability of BIOGF1K to prevent UVB-induced apoptosis, enhance matrix metalloproteinase (MMP) expression, upregulate anti-inflammatory activity, reduce sirtuin 1 expression, and melanin production using reverse transcription-polymerase chain reaction, melanin content assay, tyrosinase assay, and flow cytometry. We also evaluated the effects of BIOGF1K on the activator protein-1 signaling pathway, which plays an important role in photoaging, by immunoblot analysis and luciferase reporter gene assays. Results: Treatment of UVB-irradiated NIH3T3 fibroblasts with BIOGF1K prevented UVB-induced cell death, inhibited apoptosis, suppressed morphological changes, reduced melanin secretion, restored the levels of type I procollagen and sirtuin 1, and prevented mRNA upregulation of MMP-1, MMP-2, and cyclo-oxygenase-2; these effects all occurred in a dose-dependent manner. In addition, BIOGF1K markedly reduced activator-protein-1-mediated luciferase activity and decreased the activity of mitogen-activated protein kinases (extracellular response kinase, p38, and C-Jun N-terminal kinase). Conclusion: Our results strongly suggest that BIOGF1K has anti-photoaging activity and that BIOGF1K could be used in anti-aging cosmeceutical preparations.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4369-4376
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• 2015

Background: To investigate in-vitro antagonistic effect of low-dose liquiritigenin on gemcitabine-induced capillary leak syndrome (CLS) in pancreatic adenocarcinoma via inhibiting reactive oxygen species (ROS)-mediated signalling pathways. Materials and Methods: Human pancreatic adenocarcinoma Panc-1 cells and human umbilical vein endothelial cells (HUVECs) were pre-treated using low-dose liquiritigenin for 24 h, then added into gemcitabine and incubated for 48 h. Cell viability, apoptosis rate and ROS levels of Panc-1 cells and HUVECs were respectively detected through methylthiazolyldiphenyl-tetrazoliumbromide (MTT) and flow cytometry. For HUVECs, transendothelial electrical resistance (TEER) and transcellular and paracellular leak were measured using transwell assays, then poly (ADP-ribose) polymerase 1 (PARP-1) and metal matrix proteinase-9 (MMP9) activity were assayed via kits, mRNA expressions of p53 and Rac-1 were determined through quantitative polymerase chain reaction (qPCR); The expressions of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and PARP-1 were measured via western blotting. Results: Low-dose liquiritigenin exerted no effect on gemcitabine-induced changes of cell viability, apoptosis rate and ROS levels in Panc-1 cells, but for HUVECs, liquiritigenin ($3{\mu}M$) could remarkably elevate gemcitabine-induced decrease of cell viability, transepithelial electrical resistance (TEER), pro-MMP9 level and expression of ICAM-1 and VCAM-1 (p<0.01). Meanwhile, it could also significantly decrease gemcitabine-induced increase of transcellular and paracellular leak, ROS level, PARP-1 activity, Act-MMP9 level, mRNA expressions of p53 and Rac-1, expression of PARP-1 and apoptosis rate (p<0.01). Conclusions: Low-dose liquiritigenin exerts an antagonistic effect on gemcitabine-induced leak across HUVECs via inhibiting ROS-mediated signalling pathways, but without affecting gemcitabine-induced Panc-1 cell apoptosis. Therefore, low-dose liquiritigenin might be beneficial to prevent the occurrence of gemcitabine-induced CLS in pancreatic adenocarcinoma.

• 치위생과학회지
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• 제13권3호
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• pp.321-329
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• 2013

과산화수소는 치아미백에 널리 사용되는 물질로 과다 사용시 치수세포에 손상을 일으킬 수 있다. 본 연구의 목적은 활성산소인 과산화수소에 의해 유도되는 상아모세포의 단계별 분화와 LOX isoforms과의 관계를 밝히고자 하였다. 치수세포에 분화유도 배지와 과산화수소를 시간과 농도별로 처리한 후 LOX 유전자 발현은 RT-PCR로 측정하였고, LOX enzyme activity는 고감도 형광분석으로 확인하였다. 또한 가장 많은 발현억제를 보인 LOX와 LOXL을 선택하여 siRNA 처리 후 분화표지자의 발현변화와 LOX enzyme activity를 확인하였다. 1. 과산화수소 처리에 따라 LOX, LOXL, LOXL3 mRNA 발현은 농도와 시간 의존적으로 감소하였으나 LOXL2와 LOXL4 mRNA는 변화가 없었다. 2. 과산화수소 처리된 LOX enzyme activity는 0.3 mM과 24시간에서 가장 많은 증가를 보였다. 3. ALP, OPN, OCN의 mRNA 발현은 LOX와 LOXL siRNAs 모두에서 억제되었고, DMP1과 DSPP는 LOX siRNA에서 더 많은 억제 효과를 보였다. 하지만, 분화단계별(초기, 중기, 말기) 차이는 보이지 않았다. 4. LOX와 LOXL siRNAs를 처리하여 LOX enzyme activity를 측정한 결과 LOX siRNA를 처리한 실험군에서 더 많은 억제효과를 보였다. 이러한 결과는 상아모세포 성장과 분화과정에 낮은 농도의 과산화수소가 분화를 유도하고 여기에 LOX가 관련됨을 알 수 있었다. 결론적으로, 과산화수소는 LOX 유전자 발현조절을 통해 치수세포의 성장과 분화에서 중추적인 역할을 할 것이라고 생각된다.

• 생명과학회지
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• 제23권10호
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• pp.1239-1245
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• 2013

청미래덩굴 추출물의 주름개선 효과를 확인하기 위해 elastase 저해활성을 측정한 결과 청미래덩굴 에탄올 추출물과 열수 추출물이 $1,000{\mu}g/ml$에서 각각 41.1%, 16.3%의 활성을 나타내었으며, collagenase 저해활성 측정결과 청미래덩굴 에탄올 추출물과 열수 추출물이 $1,000{\mu}g/ml$에서 각각 96.6%, 60.0%의 활성을 나타내었다. 청미래덩굴의 에탄올 추출물의 세포생존율을 확인하기 위하여 섬유아세포(CCD-986sk)로 MTT assay에 의해 확인한 결과 $50{\mu}g/ml$ 농도에서 71.7%의 세포 생존율을 확인할 수 있었다. 섬유아 세포에서 청미래덩굴 에탄올 추출물의 pro-collagen type-1 생합성량을 확인한 결과 $50{\mu}g/ml$의 농도에서 139% 이상의 우수한 효과를 나타내었으며, MMP-1 저해활성을 측정한 결과 $50{\mu}g/ml$의 각각의 농도에서 74.9%의 활성을 나타내었다. 청미래덩굴 에탄올 추출물을 처리한 섬유아 세포에서 MMP family 중 MMP-1의 단백질 발현 및 mRNA 발현 억제 효과를 확인한 결과 MMP-1 단백질 발현과 mRNA 발현 모두 $50{\mu}g/ml$에서 각각 35%, 45%의 저해율을 나타내었다. 이러한 결과로 미루어 보아 청미래덩굴 에탄올 추출물이 주름개선용 화장품 소재로 응용이 가능할 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2419-2424
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• 2013

Guanosine-5'-diphosphate 3'-diphosphate (ppGpp) serves as alarmone in bacterial stringent responses. In this study, an affinity column was constructed by immobilizing ppGpp to NHS-Sepharose for isolating ppGpp-binding proteins. A novel ppGpp-binding protein, YjgA, was isolated and characterized by MALDI-TOF MS (matrix-assisted laser desorption ionization-time-of-flight mass spectrometry) coupled with two-dimensional gel electrophoresis. YjgA and truncated forms of YjgA were cloned and over-expressed in BL21 (DE3). The binding affinity of YjgA to ppGpp was determined by equilibrium dialysis. The interaction of YjgA with ppGpp was very specific, considering that the dissociation constant of YjgA with ppGpp was measured as $5.2{\pm}2.0{\mu}M$, while the affinities to GTP and GDP were about 60 and 30 times weaker than ppGpp. Expression of yjgA gene in Escherichia coli K-12 MG1655 was examined by reverse transcription polymerase chain reaction (RT-PCR). RT-PCR results revealed that yjgA was expressed from early to late stationary phase. The yjgA deletion mutant exhibited decreased cell number at stationary phase compared to parent strain and the over-expression of YjgA increased the cell number. These results suggested that YjgA might stimulate cell division under stationary phase. In most prokaryotic genome, about half of the protein candidates are hypothetical, that are expected to be expressed but there is no experimental report on their functions. The approach utilized in this study may serve as an effective mean to probe the functions of hypothetical proteins.

• Journal of Periodontal and Implant Science
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• 제35권2호
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• pp.345-357
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• 2005

Prostaglandin plays a significant role in the local control of bone metabolism associated with periodontal disease. ${\Delta}^{12}-PGJ_2$ is a natural $PGD_2$ metabolite that is formed in vivo in the presence of plasma. It is known for ${\Delta}^{12}-PGJ_2$ to stimulate calcification in osteoblastic cells. Bone morphogenetic protein(BMP) stimulated osteoblastic differentiation in various types of cells and greatly enhanced healing of bony defects. The purpose of this study was to evaluate the effect of rhEMP-2 on ${\Delta}^{12}-PGJ_2$ induced osteoblastic differentiation and mineralization in vitro. A human osteosarcoma cells line Saos-2 were cultured. In the test groups, 10-7M of ${\Delta}^{12}-PGJ_2$ or mixture of 10-8M of ${\Delta}^{12}-PGJ_2$ and 100ng/ml of rhBMP-2 or 100ng/ml of rhEMP-2 were added to culture media. After 1 day, 2 days and 4 days of culture period, the cell number was measured. Alkaline phosphatase activity was measure at 3 days. Reverse transcription polymerase chain reaction(RT-PCR) was performed to determine the expression of mRNA of bone matrix protein at 8 hours, 1 day and 7 days. The ability to produce mineralized nodules in rat osteoblasts(MC3T3-E1) was evaluated at 21 days. The results were as follows : 1. rhEMP-2 or mixture of rhBMP-2 and ${\Delta}^{12}-PGJ_2$ inhibited cell proliferation of human osteosarcoma cells. 2. rhEMP-2 or mixture of rhBMP-2 and ${\Delta}^{12}-PGJ_2$ stimulated alkaline phosphatase activity significantly higher than ${\Delta}^{12}-PGJ_2$ alone. 3. rhBMP-2 or mixture of rhEMP-2 and ${\Delta}^{12}-PGJ_2$ stimulated mineralization compared to ${\Delta}^{12}-PGJ_2$ alone. 4. mRNA of alkaline phosphatase, BMP-2, cbfa 1, Type I collagen were detected in the group treated with ${\Delta}^{12}-PGJ_2$/rhBMP-2, rhBMP-2 alone, ${\Delta}^{12}-PGJ_2$ alone. These results show that mixture of ${\Delta}^{12}-PGJ_2$ and rhBMP-2 causes more bone formation than ${\Delta}^{12}-PGJ_2$ alone while the bone formation effects of mixture of ${\Delta}^{12}-PGJ_2$ and rhBMP-2 are less than those of rhBMP-2 alone. Further researches would be necessary to clarify the interactions of these agents.

• Journal of Periodontal and Implant Science
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• 제37권4호
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• pp.655-669
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• 2007

Reactive oxygen species (ROS) have been implicated in the pathogenesis of various diseases. And vitamin C has shown a protective effect for the tissues. The aim of this study was to evaluate the effects of $H_2O_2$ and ascorbic acid on matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase (TIMP: TIMP-1, TIMP-2), Type 1 collagen, fibronectin, and PDLs22 level in human periodontal ligament fibroblasts (hPDLF) via reverse transcription-polymerase chain reaction (RT-PCR). hPDLF was obtained from a healthy periodontium and cultured in Dulbecco's modified Eagles's medium plus 10% fetal bone serum. The concentration of ascorbic acid in hPDLF was $50{\mu}g/ml$, and that of $H_2O_2$ in hPDLF was 0.03% and 0.00003%. Ascorbic acid only, $H_2O_2$ only and mixture of ascorbic acid and $H_2O_2$ were applied with hPDLF for 1-, 3-, and 30-min. respectively. The gene expression of MMP-1-, TIMP-1-, TIMP-2-, Type 1 collagen-, fibronectin-, and PDLs22-mRNA in hPDLF was analysed via RT-PCR. The results were as follows; 1. hPDLF in response to 30-min. incubation with 0.03% $H_2O_2$ did not show any gene expression. 2. In all the experimental groups, the gene expression of fibronectin mRNA showed the decreased tendency compared to control. 3. In all the experimental groups, the gene expression of TIMP-1 mRNA showed the tendency similar to control. 4. hPDLF in response to 30-min. incubation with 0.03% $H_2O_2$ and ascorbic acid increased mRNA induction for MMP-1. 5. In all the experimental groups, hPDLF increased mRNA induction for PDLs22, collagen type 1, and TIMP-2 compared to control. Within the limited experiments, $H_2O_2$ and ascorbic acid increased mRNA induction for PDLs22, collagen type 1, TIMP-2 in hPDLF. More research will be needed in order to confirm the relative importance of the different roles of ROS and antioxidants in hPDLF from a periodontal regeneration or repair standpoint.

• 폴리머
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• 제32권3호
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• pp.246-250
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• 2008

본 연구에서는 분해성 고분자의 종류와 제조조건에 따른 나노입자의 분산 안정성을 평가하기 위하여 광산란 입도 분석기를 이용하여 입자 크기 변화를 조사하였다. 이를 위해 생분해성 고분자인 폴리(D,L-락타이드-co-글리콜라이드) 단독과 폴리(L-락타이드)와의 블렌드, 그리고 폴리(L-락타이em)-g-폴리(에틸렌 글리콜)과의 블렌드, 세 종류를 개선된 자발적 에멀션/용매 확산 방법을 이용하여 나노입자를 제조하였다. 제조조건의 영향을 파악하기 위하여서는 나노입자의 제조시에 대표적인 분산 안정제인 폴리(비닐 알코올)(PVA)의 사용 유무의 영향을 조사하였다. 시간이 진행함에 따라 분산 안정제가 적용되지 않은 경우에서는 나노입자의 분해와 분해를 통해 붕괴된 입자의 응집에 의하여 입자의 크기가 bimodal 분포를 나타내었다. 나노입자가 분산된 수용액에 단백질 용액을 투입한 경우에는 분산 안정제인 PVA의 사용 유무에 의해 극명한 차이를 나타내었으며 PVA가 분산 안정성에 크게 기여함을 확인할 수 있었다. 또한 낮은 분자량의 폴리(에틸렌 글리콜)이 그래프트 고분자를 미량 블렌드함에 따라 입자의 단백질 흡착에 대한 분산 안정성은 침전이 일어나지 않고 1일 정도 분산 상태를 유지하는 것으로부터 일부 향상됨을 확인하였다.

• 대한화장품학회지
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• 제36권2호
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• pp.99-103
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• 2010

왁스 또는 긴사슬을 가지는 탄화수소는 동물, 식물, 광물 또는 합성에 의해 만들어 진다. 오일-왁스 겔은 립스틱과 같은 다양한 화장품 분야에 사용되어지고 있다. 예를 들면, 립스틱의 사용감촉은 오일-왁스 겔의 광택 정도에 크게 영향을 받는다. 여러 논문에서 단일 용매 또는 혼합된 용매에서의 왁스 구조에 대해서 연구가 진행되었다. 그러나 왁스 구조에 대한 연구 논문은 극히 소수에 불과하다. 이 논문의 목적은 세레신 왁스와 또 다른 왁스를 사용하여 오일-왁스 겔에서의 광택과 왁스 구조에 대한 관계를 연구하였다. 최근 들어 입술피부에서의 광택 효과는 아름다움의 척도로 알려지고 있다. 광택효과는 오일-왁스 메트릭스가 형성될 때 메트릭스 구조의 변화와 오일의 성질에 의해 좌우된다. 최근 연구에서는 세레신 왁스와 마이크로크리스탈린 왁스로부터 얻어진 오일-왁스 겔에서의 왁스 구조변화와 그에 따른 광택에 대한 영향을 보고하고 있다.