• 제목/요약/키워드: Chemistry factor

검색결과 1,221건 처리시간 0.022초

Phylogenetic analysiccccccccc of the genus Stemphylium based on elongation factor -1 alpha and calmodulin gene squences

  • Kong, D.W.;Cho, H.S.;Yu, S.H.
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.117.2-117
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    • 2003
  • The importance and diversity of the genus Stemphylium highlights the need for accurate identification of species. However, many Stemphylium isolates have been misidentified due to the use of spore size as the only identifying character. Molecular phylogenetic analyses were performed on fifty-four isolates covering 9 Stemphylium species collected in Korea. Phylogenetic analysis of the translation elongation factor -1 alpha (EF-1) and the calmodulin gene sequence data showed that Stemphylium species were segregated into seven distinct groups, most of w hichcorrelated with species identified by morphology. Analysis of EF-1 in particular was useful for establishing well- supported relationships among the species of Stemphylium.

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방향족 슬폰산들의 역상 이온쌍 크로마토그래피 (Reversed-Phase Ion-Pair Chromatography of Aromatic Sulfonic Acids)

  • 강삼우;오해범;이승석
    • 대한화학회지
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    • 제30권2호
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    • pp.224-230
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    • 1986
  • 알킬처리된 실리카(ODS)칼럼을 이용하여 역상 이온쌍 크로마토그래피방법으로 방향족 술폰산들의 분리 인자를 조사하였으며 또한 분리를 시도하였다. 반대이온으로서 브롬화 도데실 트리메틸암모늄(DTAB)을 사용하였으며, 시료의 분리인자는 반대이온의 농도, 메탄올의 농도, 전해질의 종류 및 농도, 시료 분자에 붙어있는 작용기의 종류 및 위치등에 의하여 영향을 받았다. 최적 조건하에서 몇 가지 혼합시료를 분리할 수 있었다.

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Driving Force of Inverse Electron Demand Diels-Alder Reactions of Diphenyl Tetrazines

  • Kim, Yeil;Song, Suhwan;Sim, Eunji
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.128-131
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    • 2017
  • We explore the inverse electron demand Diels-Alder reactions of tetrazines with various functional groups employing quantum calculations. In general, the rate of inverse electron demand Diels-Alder reaction depends on molecular orbital levels of electron donor and electron acceptor. Likewise, ${\pi}$ orbital of the dienophile and ${\pi}^*$ orbital of the diene is a key factor. In this work, we discuss the case where the energy of diene's ${\pi}^*$ molecular orbital is not the sole governing factor to determine the reaction rate, rather the rate shows strong correlation with the charge density of dienes.

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Electrochemical Determination of As(III) at Nanoporous Gold Electrodes with Controlled Surface Area

  • Seo, Min Ji;Kastro, Kanido Camerun;Kim, Jongwon
    • 대한화학회지
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    • 제63권1호
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    • pp.45-50
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    • 2019
  • Because arsenic (As) is a chemical substance toxic to humans, there have been extensive investigations on the development of As detection methods. In this study, the electrochemical determination of As on nanoporous gold (NPG) electrodes was investigated using anodic stripping voltammetry. The electrochemical surface area of the NPG electrodes was controlled by changing the reaction times during the anodization of Au for NPG preparation, and its effect on the electrochemical behavior during As detection was examined. The detection efficiency of the NPG electrodes improved as the roughness factor of the NPG electrodes increased up to around 100. A further increase in the surface area of the NPG electrodes resulted in a decrease of the detection efficiency due to high background current levels. The most efficient As detection efficiency was obtained on the NPG electrodes prepared with an anodization time of 50 s. The effects of the detection parameters and of the Cu interference in As detection were investigated and the NPG electrode was compared to flat Au electrodes.

수용액에서 Poly(N,N'-bispalmitoyl-1, 12-diaza-3, 4;9,10-dibenzo-5,8-cyclopentadecane)를 이용한 전이금속이온들의 흡착특성 (Adsorption Behaviors of Transition Metal Ions Using the Poly(N,N'-bispalmitoyl-1, 12-diaza-3, 4;9,10-dibenzo-5,8-cyclopentadecane) in Aqueous Solution)

  • 신영국;권수한;김해중
    • 분석과학
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    • 제9권4호
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    • pp.406-410
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    • 1996
  • The adsorption behaviors of transition metal ions on the poly(N,N'-bispalmitoyl-1, 12-diaza-3, 4;9,10-dibenzo-5,8-cyclopentadecane) has been determined by adsorption process in aqueous solution. The order of concentration factor(CF) and the amount of adsorption were Cu(II)

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Phenolic Constituents with Inhibitory Activity against NFAT Transcription from Desmos chinensis

  • Kiem Phan Van;Minh Chau Van;Huang Hoang Thanh;Lee Jung Joon;Lee Im Seon;Kim Young Ho
    • Archives of Pharmacal Research
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    • 제28권12호
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    • pp.1345-1349
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    • 2005
  • Six phenolic constituents, 2-methoxybenzyl benzoate (1), negletein (2), 2',3'-dihydroxy-4',6'­dimethoxydihydrochalcone (3), 5,6-dihydroxy-7-methoxy-dihydroflavone (4), astilbin (5), and quercitrin (6) were isolated from the methanol extract of the dried leaves of Desmos chinensis. Their structures were elucidated from spectral and chemical data. Of these constituents, compounds 2 ($IC_{50}$: 3.89 $\pm$ 0.39 $\mu$M) and 3 ($IC_{50}$: 9.77 $\pm$ 0.26 $\mu$M) exhibited potent inhibitory activity against nuclear factor of activated T cells (NFAT) transcription factor, and compound 1 ($IC_{50}$: 28.4 $\pm$ 2.62 $\mu$M) exhibited moderate inhibitory activity.

Synthesis of Novel Organic Dyes Containing Coumarin Moiety for Solar Cell

  • Choi, Hyun-Bong;Baik, Chul;Kim, Hyun-Jun;Kim, Jeum-Jong;Song, Ki-Hyung;Kang, Sang-Ook;Ko, Jae-Jung
    • Bulletin of the Korean Chemical Society
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    • 제28권11호
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    • pp.1973-1979
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    • 2007
  • Novel organic dyes, JK-34, JK-35 and JK-36 containing bis-dimethylfluorenyl amino coumarin unit are designed and synthesized. Nanocrystalline TiO2 dye-sensitized solar cells were fabricated using these dyes. Under standard global AM 1.5 solar condition, the JK-34 sensitized cell gave a short circuit photocurrent density of 10.05 mA cm?2, open circuit voltage of 0.65 V, and a fill factor of 0.68, corresponding to an overall conversion efficiency η of 4.54%. We found that the power conversion efficiency was shown to be quite sensitive to the structural modifications of bridging thiophene moiety.

Hyaluronic acid and proteoglycan link protein 1 suppresses platelet-derived growth factor-BB-induced proliferation, migration, and phenotypic switching of vascular smooth muscle cells

  • Dan Zhou;Hae Chan Ha;Goowon Yang;Ji Min Jang;Bo Kyung Park;Bo Kyung Park;In Chul Shin;Dae Kyong Kim
    • BMB Reports
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    • 제56권8호
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    • pp.445-450
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    • 2023
  • The development of atherosclerotic cardiovascular disease is associated with the phenotypic switching of vascular smooth muscle cells (SMCs) from a contractile to a synthetic state, leading to cell migration and proliferation. Platelet-derived growth factor-BB (PDGF-BB) modulates this de-differentiation by initiating a number of biological processes. In this study, we show that gene expression of hyaluronic acid (HA) and proteoglycan link protein 1 (HAPLN1) was upregulated during differentiation of human aortic SMCs (HASMCs) into a contractile state, but downregulated upon during PDGF-BB-induced dedifferentiation. This is the first study showing that the treatment of HASMCs with full-length recombinant human HAPLN1 (rhHAPLN1) significantly reversed PDGF-BB-induced decrease in the protein levels of contractile markers (SM22α, α-SMA, calponin, and SM-MHC), and inhibited the proliferation and migration of HASMCs induced by PDGF-BB. Furthermore, our results show that rhHAPLN1 significantly inhibited the phosphorylation of FAK, AKT, STAT3, p38 MAPK and Raf mediated by the binding of PDGF-BB to PDGFRβ. Together, these results indicated that rhHAPLN1 can suppress the PDGF-BB-stimulated phenotypic switching and subsequent de-differentiation of HASMCs, highlighting its potential as a novel therapeutic target for atherosclerosis and other vascular diseases.

Computational Study on the Binding of Aux/IAA17 and ARF5 Involved in Auxin's Transcriptional Regulation using Molecular Docking

  • Kwon, Sohee;Lee, Gyu Rie;Seok, Chaok
    • EDISON SW 활용 경진대회 논문집
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    • 제6회(2017년)
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    • pp.16-26
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    • 2017
  • Auxin response factor (ARF) and Aux/IAA transcriptional repressor family proteins play a major role in auxin's signalling process. Using the GALAXY protein modelling programs, monomer, dimer and oligomer structures of Aux/IAA17 and ARF5 protein were predicted based on the known experimental structures. By analysing the proposed complex structures, key interacting residues on binding site could be determined, and further suggestions for experimental studies were made.

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