• 제목/요약/키워드: ${\lambda}_{max}$

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근접장 마이크로파 현미경을 이용한 로돕신의 광학적 특성 연구 (Optical Characterization of Sensory Rhodopsin II Thin Films using a Near-field Scanning Microwave Microscope)

  • 유경선;김송희;윤영운;이기진;이정하;최아름;정광환
    • 한국전기전자재료학회논문지
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    • 제20권1호
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    • pp.80-85
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    • 2007
  • We report the electro-optical properties of the sensory rhodopsin II using a near-field scanning microwave microscope(NSMM). Rhodopsin was known as a photoreceptor pigment with a retinal as a chromophore via a protonated Schiff base and consists of seven ${\alpha}-helical$ transmembrane segments. The sensory rhodopsin II, expressing E. coli UT5600 with endogenous retinal biosynthesis system and purified with $Ni^{-2}-NTA$ affinity chromatography in the presence of 0.02 % DM (Dodecyl Maltoside) from Natronomonas pharaonis. We measured the absorption spectra and the transients difference of sensory rhodopsin II from Natronomonas pharaonis using a UV/VIS spectrophotometer with Nd-Yag Laser (532 nm). The absorption spectra of NpSR II showed a typical rhodopsin spectrum with a left shoulder region and the photointermediates spectra of NpSR II-ground state (${\lambda}max=498\;nm$), NpSR II-M state (${\lambda}max=390\;nm$), and NpSR II-O state (${\lambda}max=550\;nm$) during the photocycle. The observed photocycle reaction was confirmed by measuring the microwave reflection coefficient $S_{11}$ at an operating frequency of f=3.93-3.95 GHz and compared with the results of a photocycle of NpSR II.

Inactivation of Brain Succinic Semialdehyde Reductase by o-Phthalaldehyde

  • Choi, Soo-Young;Song, Min-Sun;Lee, Byung-Ryong;Jang, Sang-Ho;Lee, Su-Jin;Park, Jin-Seu;Choe, Joon-Ho;Cho, Sung-Woo
    • BMB Reports
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    • 제28권2호
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    • pp.112-117
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    • 1995
  • Succinic semialdehyde reductase was inactivated by o-phthalaldehyde. The inactivation followed pseudo-first order kinetics, and the second-order rate constant for the inactivation process was 28 $M^{-1}s^{-1}$ at pH 7.4 and $25^{\circ}C$. The absorption spectrum ($\lambda_{max}$ 337 nm) and fluorescence excitation ($\lambda_{max}$ 340 nm) and fluorescence emission spectra ($\lambda_{max}$ 409 nm) were consistent with the formation of an isoindole derivative in the catalytic site between a cysteine and a lysine residue approximately about 3 $\AA$ apart. The substrate, succinic semialdehyde, did not protect enzymatic activity against inactivation, whereas the coenzyme NADPH protected against o-phthaladehyde induced inactivation of the enzyme. About 1 isoindole group per mol of the enzyme was formed following complete loss of enzymatic activity. These results suggest that the amino acid residues of the enzyme participating in a reaction with o-phthalaldehyde are cysteinyl and lysyl residues at or near the NADPH binding site.

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Presentation of central motion techniques: limpness motion function and limpness sensory unit function

  • Kim, Jeong-lae;Kim, Kyu-dong
    • International Journal of Advanced Culture Technology
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    • 제4권3호
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    • pp.56-61
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    • 2016
  • Central motion techniques are to mention the central-motion by the limpness motion function and limpness sensory unit function on the body. Central body motion is consisted of the limpness central function by the central body system. To evaluate the signal of central body motion, we are investigated a limpness value of the central function by the central body function on the static state. The concept of limpness motion function was checked the reference of limpness motion signal and limpness sensory signal by the central motion body. For assessment on the limpness sensory variation of the maximum and average in terms of central motion from the static function, and limpness value that was a limpness value of the vision condition of the Vi-${\lambda}_{MAX-AVG}$ with $8.71{\pm}-3.2units$, that was a limpness value of the vestibular condition of the Ve-${\lambda}_{MAX-AVG}$ with $3.05{\pm}-6.52units$, that was a limpness value of the somatosensory condition of the So-${\lambda}_{MAX-AVG}$ with $2.4{\pm}1.9units$. The static sensory motion was made mention of check out at the condition of the limpness sensory unit motion for the comparable values of limpness central motion that was expressed the analysis capacity by the limpness nerve system. Limpness sensory system will be to propose of the minute motion by static central motion situation and was to imply a limpness motion data of static body sensory function.

개질 영가철을 이용한 산성 및 염기성 염료의 탈색 특성 (Decolorization Characteristics of Acid and Basic Dyes Using Modified Zero-valent Iron)

  • 최정학;김영훈
    • 한국환경과학회지
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    • 제25권12호
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    • pp.1717-1726
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    • 2016
  • In this study, the reductive decolorization of three acid and basic dyes using modified zero-valent iron (i.e., acid-washed iron (Aw/Fe) and palladium coated iron (Pd/Fe)) at various pH conditions (pH 3~5) was experimentally investigated and the decolorization characteristics were evaluated by analyzing the absorbance spectra and reaction kinetics. In the case of acid dyes such as methyl orange and eriochrome black T, color removal efficiencies increased as initial pH of the dye solution decreased. However, the color removal of methylene blue, a basic dye, was not affected much by the initial pH and more than 70% of color was removed within 10 min. During the decolorization reaction, the absorbance of methyl orange (${\lambda}_{max}=464nm$) and eriochrome black T (${\lambda}_{max}=528nm$) decreased in the visible range but increased in the UV range. The absorbance of methylene blue (${\lambda}_{max}=664nm$) also decreased gradually in the visible range. Pseudo-zero order, pseudo-first order, and pseudo-second order kinetic models were used to analyze the reaction kinetics. The pseudo-second order kinetic model was found to be the best with good correlation. The decolorization reaction rate constants ($k_2$) of methylene blue were relatively higher than those of methyl orange and eriochrome black T. The reaction rate constants of methyl orange and eriochrome black T increased with a decrease in the initial pH.

산처리에 의한 찹쌀 전분의 성질 변화 (Properties of Lintnerized Waxy Rice Starches)

  • 박양균;김성곤;김관
    • 한국식품영양과학회지
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    • 제22권5호
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    • pp.596-602
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    • 1993
  • 신선찰벼와 한강찰벼 전분을 산처리하여 이호학적 성질, differential scanning calrorimetry 및 효소에 의한 가수분해율의 차이를 비교 검토하였다. 산 가수분해율은 한강찰벼가 약간 높았으며, 산처리에 따라 가용성 선형물질이 분해되어 ${\lambda}_{max}$와 청가는 감소하였고 또 물결합능력, 용해도 및 결정도는 증가하였으나 팽윤력은 감소하였다. 요오드 반응에 의한 최대흡수파장은 한강찰벼가 높았으나 최대흡수파장 및 680nm에서 흡광도는 시료간에 차이가 없었다. 물결합 능력과 용해도는 신선찰벼가 높았으나 팽윤력은 한강찰벼가 높았다. 가열에 의한 광투과도는 신선찰벼가 낮아서 열에 대한 안정성이 높았다. KSCN에 의한 겔부피는 신선찰벼가 커서 용출물질량이 많았다. 산처리중 전분의 결정형태는 A형이 유지되었으며 상대결정도는 신선찰벼가 높았다. DSC특성값은 산처리에 따라 감소하였으며, glucoamylase에 의한 가수분해율은 산처리에 따라 증가하여 산처리 48시간에 신선찰벼는 98%, 한강찰벼는 96%로 전체적으로 신선찰벼가 높았다.

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염욕의 pH와 매염제의 변화에 따른 코치닐의 염색성 연구 I -면직물을 중심으로- (A Study on Cochineal Dyeing by Various Mordants and pH Conditions I -Treatment on Cotton Fabric-)

  • 김경선;전동원;김종준;최인려
    • 복식문화연구
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    • 제13권2호
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    • pp.240-247
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    • 2005
  • In this study, cotton fabric specimens were pre-mordanted using Sn, Al, Cu, Cr, and Fe, and subsequently dyed using cochineal, maintaining the pH of the dye bath constant using pH buffer solutions of 4, 5, 6, 7, and 8. In the cases of Al, Cr, and Sn mordanting, the dye-uptake was well accomplished in the acidic range of pH 4 and 5. However, the dye-uptake was not accomplished in the range over pH 6. In the cases of Cu and Fe mordanting, however, the pH value did not affect the dye-uptake and the dyeability in the alkaline range was not decreased remarkably. In the case of non-mordant, the dye-uptake was not accomplished at all, and the Cu and Fe mordanting gave rise to the best dyeability. In the cases of non-mordanting and Al, Cu mordanting, there was no change in the $\lambda_{max}$, and in the cases of Sn and Cr mordanting, the $\lambda_{max}$ moved toward the shorter wavelength. In the case of Fe mordanting only, the $\lambda_{max}$ moved gradually toward the longer wavelength, and due to the pH effect deep-dyeing effect was revealed.

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Serratia marcescens 균주로부터 추출한 Prodigiosin의 흡수분광학적 연구 (Absorption Spectroscopic Studies of Prodigiosin Extracted from Serratia Marcescens Strain)

  • 박희억
    • 한국응용과학기술학회지
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    • 제36권1호
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    • pp.355-361
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    • 2019
  • Serratia marcescens 2354(ATCC 25419) 균주로부터 추출한 붉은 색소는 prodigiosin (PG)이었고, 이를 methanol에 녹여 자외선 및 가시광선 흡수 스펙트라를 측정한 결과 537 nm의 최대흡수파장 (${\lambda}_{max}$)을 갖는 산성용액에서의 전형적인 PG의 흡수 스펙트라이었다. 또한 methanol 용액에서 PG의 농도를 $1.0{\times}10-5M$에서 $9.0{\times}10-5M$로 증가시키면, 537 nm의 흡수강도는 증가하고 467 nm의 흡수강도는 감소하였으며, 500 nm에서 isosbestic point가 관측되었다. 이러한 현상은 537 nm와 467 nm가 각각 산과 염기용액에서의 PG 흡수대이고, 500 nm의 isosbestic point 등을 고려하면 가역적 산-염기 평형반응에 의한 결과라고 볼 수 있다. 한편 pH, 4.75의 acetic acid 완충용액에서 PG의 농도를 $6.0{\times}10^{-4}M$에서 $1.0{\times}10^{-4}M$로 감소시키면 500 nm에서 ${\lambda}_{max}$를 가지는 새로운 흡수대가 나타난다. 이 흡수대는 pH 4.75의 수용액에서만 나타나는 것으로 같은 pH의 순수한 methanol 용액에서는 나타나지 않는다. 이는 PG 분자가 $H_2O$에 의해 ${\alpha}$-이성질체에서 ${\beta}$-이성질체로의 전환에 기인하는 것이다. 즉 PG의 색변화는 용액의 농도 및 용매의 특성에 의해서도 일어날 수 있음을 확인하였다.

Self-Assembled and Alternative Porphyrin-Phthalocyanine Array

  • Kwag, Gwang-Hoon;Park, Eun-Joo;Kim, Sung-Hyun
    • Bulletin of the Korean Chemical Society
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    • 제25권2호
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    • pp.298-300
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    • 2004
  • An alternative molecular porphyrin-phthalocyanine aggregate was prepared and characterized with UV-visible and X-ray absorption spectroscopies. UV-visible experiments evidence 1-dimensional porphyrin-phthalo-cyanine array formed by mixing $SnTPPCl_2 ({\lambda}_{max}=429,\;{\varepsilon}=2.4{\times10^ 5 /M{\cdot}cm)\;and\;NiPc(OBu)_8({\lambda}_{max}=744 nm,\;{\varepsilon}= 2.0{\times}10^ 5 /M{\cdot}cm)$ in solution. In the UV-visible spectrum of the porphyrin-phthalocyanine array, $(SnPNiPc)_n$, a new Q-band appeared at 844 nm with decrease of the Q-band peak of $NiPc(OBu)_8$ at 744 nm. The red-shift of Q-band evidences an alternative porphyrin-phthalocyanine array formed in solution through metal-halide interaction rather than ${\pi}-{\pi}$ facial interaction, in which nickel of $NiPc(OBu)_8$ coordinates with chloride of $SnTPPCl_2$ through self assembly. Ni K-edge XANES (X-ray absorption near edge structure) spectra also support the axial ligation of nickel to chloride. The square planar structure of $NiPc(OBu)_8$ turns to an octahedral structure in (SnPNiPcSnP) by axial ligation. A higher energy-shift (0.2 eV) of the preedge peak of (SnPNiPcSnP) indicaties partial oxidation of nickel by charge transfer from NiPc$(OBu)_8$ to SnTPPCl$_2$.

스틸벤의 치환기 효과에 대한 분자궤도함수론적 해석 (Mo Interpretation for the Substituent Effect of Stilbenes)

  • 임성미;박병각;이갑용
    • 대한화학회지
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    • 제36권1호
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    • pp.38-43
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    • 1992
  • 치환 스틸벤 계열에 대해 HMO법으로 Hammett치환기 상수를 해석하였다. 이 계열에서 치환기 상수에 대한 유도효과와 공명효과의 기여를 양자화학적 지수로 취하여 계산한 이론값이 Hammett 치환기 상수 ${\sigma}_p$와 병행성이 있음을 알았으며 이 이론값으로 치환 스틸벤의 쌍극자능륙에 미치는 치환기 효과를 설명할 수 있었다. 아울러 이 화합물의 전자전이에 대한 최대 흡수파장$({\lambda}_{max})$은 HOMO와 LUMO 에너지의 창에 의존됨이 확인되었다.

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