• 제목/요약/키워드: chain formation

검색결과 592건 처리시간 0.025초

기능성 유기 초박막을 이용한 $NO_2$ 가스센서 개발을 위한 기초 연구 (Basic Studies for the Development of the $NO_2$ Gas Sensor Using Functional Organic Ultrathin Film)

  • 손병청;임병오;김용인;손태원;신동명;주재백;정귀영;김영관;강우형;이병호
    • 한국응용과학기술학회지
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    • 제12권1호
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    • pp.125-131
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    • 1995
  • Ultra thin films of Tetra-3-hexadecylsulphamoylcopperphthalocyanine(HDSM-CuPc) were formed on various substrates by Langmuir-Blodgett method, where HDSM-CuPc was synthesized by attaching long-chain alkylamine(hexa-decylamine) to CuPc. The reaction product was identified with FT-IR, UV-visible absorption spectroscopies, elemental analysis and thin layer chromatography. The formation of Ultrathin Langmuir-Blodgett(LB) films of HDSM-CuPc was confirmed by FT-IR and UV-visible spectroscopies. A quartz piezoelectric crystal coated with LB films of HDSM-CuPc was examined as a gas sensor for $N0_2$ gas. HDSM-CuPc LB films were transferred to a quartz crystal microbalance(QCM) in the form of Z-type multilayers. Response characteristics of film-coated QCM to $NO_2$ gas concentrations over a range of $100{\sim}600ppm$ have been tested with a thickness of $5{\sim}20$ layers of HDSM-CuPc. Changes in frequency by adsorption of $NO_2$ were increased With the number of LB layers and $NO_2$ concentration, but the response time was slow.

수소 결합에 의한 삼차원의 Copper(II) 거대고리 착물과 2,5-Pyridinedicarboxylate와의 자기조립 (Self-Assembly of Three-Dimensional Copper(II) Macrocyclic Complex with 2,5-Pyridinedicarboxylate Linked by Hydrogen Bond)

  • 최기영;류해일;김용선
    • 대한화학회지
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    • 제47권2호
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    • pp.104-108
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    • 2003
  • $[Cu(L)]Cl_2{\cdot}2H_2O(L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^{1.18},0^{7.12}]docosane)$과 2,5-pyridinedicarboxylate(pdc)의 반응으로부터 $[Cu(L)(H_2O)](pdc){\cdot}6H_2O(1)$가 합성되었다. 화합물 1의 구조가 X-ray 회절법 및 분광학적 방법으로 규명되었다. 중심 copper 원자는 거대고리 리간드로부터 4개의 이차 아민과 축방향 위치의 물분자로 결합된 약간 일그러진 사각뿔 구조를 갖는다. 또한 분자간 수소결합은 삼차원의 분자구조를 형성한다.

Nutrient dynamics study of overlying water affected by peroxide-treated sediment

  • Haque, Niamul;Kwon, Sung-Hyun
    • Journal of Ecology and Environment
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    • 제41권9호
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    • pp.235-245
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    • 2017
  • Background: Loading of excess nutrient via bioremediation of polluted sediment to overlying water could trigger anoxia and eutrophication in coastal area. The aim of this research was to understand the changes of overlying water features such as dissolved oxygen (DO); pH; oxidation reduction potential (ORP); $chlorophyll-{\alpha}$ ($Chl-{\alpha}$); and nitrogen nutrients ammonia ($N-NH_4{^+}$), nitrate ($N-NO_3{^-}$), and nitrite ($N-NO_2^-$) when the sediment was not treated (control) and treated by calcium peroxide for 5 weeks. Methods: The water samples were analyzed for measuring physical and chemical properties along with the sediment analyzed by polymerase chain reaction (PCR) including denaturing gradient gel electrophoresis (DGGE) for identifying the phylogenetic affiliation of microbial communities. Results: Results showed that due to the addition of calcium peroxide in sediment, the overlying water exposed the rise of dissolve oxygen, pH, and ORP than control. Among the nitrogen nutrients, ammonia inhibition was higher in calcium peroxide treatment than control but in case of nitrate inhibition, it was reversed than control. $Chlorophyll-{\alpha}$ was declined in treatment column water by 30% where it was 20% in control column water. Actibacter and Salegentibacter group were detectable in the calcium-peroxide-treated sediment; in contrary, no detectable community ware found in control sediment. Both phylogenetic groups are closely related to marine microflora. Conclusions: This study emphasizes the importance of calcium peroxide as an oxygen release material. Interaction with peroxide proved to be enhancing the formation of microbial community that are beneficial for biodegradation and spontaneity of nutrient attenuation into overlying water.

새로운 생체적합성 폴리펩티드공중합체의 합성과 혈액적합성에 관한 연구 : 측쇄에 에틸렌글리콜을 함유하는 폴리펩티드 공중합체의 혈액적합성 (Synthesis and Blood Compatibility of New Biocompatible Copolypeptides : Blood Compatibility of Copolypeptide Having Ethylene Glycol Oligomers Substituted in the Side Chain)

  • 강인규;박상동;조종수;성용길
    • 대한화학회지
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    • 제36권6호
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    • pp.947-954
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    • 1992
  • Poly (γ-benzyl L-glutamate) (PBLG)와 말단에 아미노기를 갖는 Polyethylene glycol (PEG)의 치환반응을 행하여 PEG-grafted PBLG (PEG-g-PBLG)를 합성하였다. 또한 PEG-g-PBLG 필름표면에 ethanolamine(EA)을 치환반응하여 표면에 히드록시그룹을 갖는 PEG-g-PBLG-EA 필름을 얻었다. 폴리펩티드중합체와 혈액성분과의 상호작용에 관한 실험결과, PEG-g-PBLG 상에서의 혈소판의 점착율 및 형태변화는 PEG-g-PBLG-EA보다 적게 나타났고, PEG-g-PBLG상에서의 혈장 단백질의 응고시간은 PEG-g-PBLG-EA 또는 PBLG의 응고시간보다 길게 나타났다. 이들 결과는 혈액응고시간 및 혈액응고량을 조사한 실험결과와 일치하였다. 따라서 폴리펩티드상의 히드록시그룹은 혈액성분과의 상호작용을 강하게 하여 혈액적합성이 저하하는 반면, PEG-g-PBLG는 비교적 좋은 혈액적합성을 나타냄을 알 수 있었다.

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Sodium Dodecylbenzene Sulfonate 수용액의 분해반응에서 초음파 효과 (Effect of Ultrasound on the Decomposition of Sodium Dodecylbenzene Sulfonate in Aqueous Solution)

  • 임봉빈
    • 대한화학회지
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    • 제48권6호
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    • pp.561-567
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    • 2004
  • 계면활성제 중 sodium dodecylbenzene sulfonate(DBS) 수용액에 초음파(200 W, 6 $W/cm^2$)를 조사하여 주파수, 용존가스 및 농도에 따른 분해경향을 조사하였다. 주파수에 따른 초음파 분해속도는 50 kHz와 600 kHz보다 200 kHz에서 가장 빠른 것으로 나타났다. 200 kHz의 초음파를 이용한 DBS의 분해반응에서는 산소를 이용하였을 때 가장 빠른 분해속도를 나타내었으며, 질소의 경우가 가장 늦은 분해속도를 나타내 초음파반응에 사용된 용존가스(산소, 공기, 질소, 아르곤, 헬륨)의 물리적성질과 활성라디칼의 생성에 의해 분해속도가 달라졌음을 알 수 있다. DBS의 농도에 따른 초음파분해 경향을 보면, 1 mM 까지 분해속도의 감소가 뚜렷하게 나타났으며, DBS의 critical micelle concentration(3 mM) 부근을 기준으로 분해속도의 변화가 거의 나타나지 않아 계면활성제의 미셀형성이 초음파에 의해 유도되는 라디칼에 의한 산화반응과 버블계면에서의 열분해반응에 영향을 미치는 것으로 생각된다.

Induction of Mac-2BP by nerve growth factor is regulated by the PI3K/Akt/NF-κB-dependent pathway in the HEK293 cell line

  • Park, Yuk-Pheel;Choi, Seung-Chul;Kim, Bo-Yeon;Kim, Jong-Tae;Song, Eun-Young;Kang, Seong-Ho;Yoon, Do-Young;Paik, Sang-Gi;Kim, Kwang-Dong;Kim, Jong-Wan;Lee, Hee-Gu
    • BMB Reports
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    • 제41권11호
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    • pp.784-789
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    • 2008
  • Mac-2BP is a ligand of the galectin family that has been suggested to affect tumor proliferation and metastasis formation. We assessed Mac-2BP expression at the transcriptional and translational levels to evaluate nerve growth factor (NGF)-induced Mac-2BP expression. A time kinetic analysis using reverse transcription-polymerase chain reaction showed that NGF-induced Mac-2BP transcript levels were 4-5 times higher than in controls. Mac-2BP enzyme-linked immunosorbent assay and immuno-fluorescence staining showed a 2-3-fold increase in intracellular and secreted Mac-2BP as a result of NGF stimulation. This increase was regulated by Akt activation and NF-${\kappa}B$ binding. p65 and p50-NF-${\kappa}B$ are major transcriptional factors in the Mac-2BP promoter region, and were shown to be regulated in accordance with the Akt activation states. Collectively, these results suggest that NGF induces Mac-2BP expression via the PI3K/Akt/NF-${\kappa}B$ pathway.

Effect of cell-penetrating peptide-conjugated estrogen-related receptor ${\beta}$ on the development of mouse embryos cultured in vitro

  • Yang, Ning Jie;Seol, Dong-Won;Jo, Junghyun;Jang, Hyun Mee;Yoon, Sook-Young;Lee, Dong Ryul
    • Clinical and Experimental Reproductive Medicine
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    • 제41권1호
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    • pp.1-8
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    • 2014
  • Objective: Estrogen related receptor ${\beta}$ (Esrrb) is a member of the orphan nuclear receptors and may regulate the expression of pluripotencyrelated genes, such as Oct4 and Nanog. Therefore, in the present study, we have developed a method for delivering exogenous ESRRB recombinant protein into embryos by using cell-penetrating peptide (CPP) conjugation and have analyzed their effect on embryonic development. Methods: Mouse oocytes and embryos were obtained from superovulated mice. The expression of Oct4 mRNA and the cell number of inner cell mass (ICM) in the in vitro-derived and in vivo-derived blastocysts were first analyzed by real time-reverse transcription-polymerase chain reaction and differential staining. Then 8-cell embryos were cultured in KSOM media with or without $2{\mu}g/mL$ CPP-ESRRB protein for 24 to 48 hours, followed by checking their integration into embryos during in vitro culture by Western blot and immunocytochemistry. Results: Expression of Oct4 and the cell number of ICM were lower in the in vitro-derived blastocysts than in the in vivo-derived ones (p<0.05). In the blastocysts derived from the CPP-ESRRB-treated group, expression of Oct4 was greater than in the non-treated groups (p<0.05). Although no difference in embryonic development was observed between the treated and non-treated groups, the cell number of ICM was greater in the CPP-ESRRB-treated group. Conclusion: Treatment of CPP-ESRRB during cultivation could increase embryos' expression of Oct4 and the formation rate of the ICM in the blastocyst. Additionally, an exogenous delivery system of CPP-conjugated protein would be a useful tool for improving embryo culture systems.

X선 산란분석법을 이용한 액정에멀젼 구조분석 (Structure Analysis of Liquid Crystal Emulsions Using X-ray Scattering Analysis)

  • 박소현;김수지;노민주;이준배;박수남
    • 대한화장품학회지
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    • 제42권3호
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    • pp.297-302
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    • 2016
  • 본 연구에서는 $C_{12-20}$ 알킬글루코사이드, $C_{14-22}$ 알코올 및 베헤닐알코올로 구성된 액정에멀젼을 제조하고 다양한 분석장비를 이용하여 구조분석을 실시하였다. 먼저 제조한 액정에멀젼을 편광현미경과 cryo-SEM을 이용하여 각각 액정에멀젼의 특징인 maltese cross 무늬와 다층 구조를 확인하였다. 또한, DSC를 이용하여 액정상 형성을 확인하였고, small angle x-ray scattering (SAXS) 분석을 통하여 약 $305{\AA}$의 층간 간격을 갖는 다층 라멜라 구조를 확인하였다. 한편, wide angle x-ray scattering (WAXS) 분석을 통해 제조된 액정에멀젼의 라멜라 구조를 이루고 있는 알킬 사슬 간 배열이 사방정계 구조로 되어 있음을 확인할 수 있었다. 액정에멀젼 구조 연구를 통해 얻어진 다양한 물성 정보는 향후 산업적으로 많이 이용될 것으로 기대된다.

Nuclear Factor I-C 과발현과 발현억제가 MDPC-23 상아모세포주의 상아질 기질유전자 발현에 미치는 영향 (The Effect of Over-expression and Inactivation of Nuclear Factor I-C on the Dentin Matrix Gene Expression of MDPC-23 Odontoblasts)

  • 배현숙;조영식
    • 치위생과학회지
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    • 제9권4호
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    • pp.427-433
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    • 2009
  • 본 연구는 상아모세포의 분화와 상아질 형성과정에서 필수적인 인자로 알려진 NFI-C가 상아모세포 기질단백질의 발현에 미치는 영향을 알아보기 위하여, MDPC-23 상아모세포에 NFI-C 유전자를 과발현 시키거나 발현억제시킨 후 상아질 기질단백질 유전자들의 발현을 RT-PCR로 분석한 결과 다음과 같은 결론을 얻었다. 1. MDPC-23 세포에서 NFI-C mRNA는 NFI-C 과발현후에 현저히 증가하였으며, NFI-C 발현억제 후에는 감소하였다. 2. NFI-C가 과발현된 MDPC-23 세포는 NFI-C 단백질이 핵과 세포질에서 뚜렷이 관찰되었으나, NFI-C 발현이 억제된 MDPC-23 세포에서는 NFI-C 단백질의 발현이 대조군에 비하여 현저히 감소하였다. 3. NFI-C 발현이 억제된 MDPC-23 세포는 대조군에 비하여 I형 아교질, OC, 및 DSPP mRNA의 발현은 감소하였으나 BSP의 발현은 증가하였다. ALP와 DMP4의 발현은 NFI-C 발현억제 후에도 변화가 없었다. 4. NFI-C가 과발현된 MDPC-23 세포에서는 ALP와 DMP4 mRNA의 발현은 대조군에 비하여 증가하였으며 I형 아교질, OC, DSPP, 및 BSP의 발현은 감소하였다.

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Evaluation of antibacterial activity and osteoblast-like cell viability of TiN, ZrN and $(Ti_{1-x}Zr_x)N$ coating on titanium

  • Ji, Min-Kyung;Park, Sang-Won;Lee, Kwangmin;Kang, In-Chol;Yun, Kwi-Dug;Kim, Hyun-Seung;Lim, Hyun-Pil
    • The Journal of Advanced Prosthodontics
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    • 제7권2호
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    • pp.166-171
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    • 2015
  • PURPOSE. The aim of this study was to evaluate antibacterial activity and osteoblast-like cell viability according to the ratio of titanium nitride and zirconium nitride coating on commercially pure titanium using an arc ion plating system. MATERIALS AND METHODS. Polished titanium surfaces were used as controls. Surface topography was observed by scanning electron microscopy, and surface roughness was measured using a two-dimensional contact stylus profilometer. Antibacterial activity was evaluated against Streptococcus mutans and Porphyromonas gingivalis with the colony-forming unit assay. Cell compatibility, mRNA expression, and morphology related to human osteoblast-like cells (MG-63) on the coated specimens were determined by the XTT assay and reverse transcriptase-polymerase chain reaction. RESULTS. The number of S. mutans colonies on the TiN, ZrN and $(Ti_{1-x}Zr_x)N$ coated surface decreased significantly compared to those on the non-coated titanium surface (P<0.05). CONCLUSION. The number of P. gingivalis colonies on all surfaces showed no significant differences. TiN, ZrN and $(Ti_{1-x}Zr_x)N$ coated titanium showed antibacterial activity against S. mutans related to initial biofilm formation but not P. gingivalis associated with advanced periimplantitis, and did not influence osteoblast-like cell viability.