• 한국미생물·생명공학회지
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• 제17권1호
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• pp.74-80
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• 1989

광합성 세균의 수소생성 향상을 위한 노력의 일환으로 수소생성능이 좋은 Rhodopseudomonas E15-1 을 고정화하여 수소생성에 적당한 조건을 조사하였다. 담체로 4%의 alginate를 사용하였을 때 수소생성량이 많았으며 고정화함에 따라 산소. 질소에 대한 억제효과를 덜 받았다. Alginate 고정화 세포는 그 지름을 2mm 이하로 하는 것이 겔내로의 확산저항이 적으므로 적당했다. 여러가지 유기물을 활용하여 수소를 생성할 수 있었으며 특히 citrate, fumarate와 malate 같은 유기산의 경우 30mM의 농도가 수소생성에 있어서 적당하였다. 또한 고정화세포를 이용한 계속적인 수소생성에 있어서 20일부터 활성이 감소하기는 하나 겔의 구조적 안정성은 30일까지 유지되었다.

• Rapid Communication in Photoscience
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• 제4권2호
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• pp.37-40
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• 2015

To examine the photosensitized biomolecules damaging activity, dimethoxyP(V)tetrakis(2-naphthyl)porphyrin (NP) and dimethoxyP(V)tetraphenylporphyrin (PP) were synthesized. The naphthyl moiety of NP hardly deactivated the photoexcited P(V)porphyrin ring in ethanol. In aqueous solution, the naphthyl moiety showed the quenching effect on the photoexcited porphyrin ring, possibly through electron transfer and self-quenching by a molecular association. Binding interaction between human serum albumin (HSA), a water soluble protein, and these porphyrins could be confirmed by the absorption spectral change. The apparent association constant of NP was larger than that of PP. It is explained by that more hydrophobic NP can easily bind into the hydrophobic pockets of HSA. The photoexcited PP effectively induced damage of the tryptophan residue of HSA, through electron transfer-mediated oxidation and singlet oxygen generation. NP also induced HSA damage during photo-irradiation and the contributions of the electron transfer and singlet oxygen mechanisms were speculated. The electron transfer-mediated mechanism to the photosensitized protein damage should be advantageous for photodynamic therapy in hypoxic condition. The quantum yield of the HSA photodamage by PP was significantly larger than that of NP. The quenching effect of the naphthyl moiety is considered to suppress the photosensitized protein damage. In conclusion, the naphthalene substitution to the P(V)porphyrins can enhance the binding interaction with hydrophobic biomacromolecules such as protein, however, this substitution may reduce the photodynamic effect of P(V)porphyrin ring in aqueous media.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.432-442
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• 2011

Anodized tubular $TiO_2$ electrodes (ATTEs) with three noticeably different lengths are prepared to determine their optimum length for the photo-driven activity in the reaction of Cr(VI) reduction and hydrogen evolution. The ATTEs with ethylene glycol have longer $TiO_2$ tubes (7-15.6 ${\mu}m$) than those with hydrfluoric acid (0.6-0.8 ${\mu}m$). These samples, which differ only in the length of the tubes, with a wall thickness of ca. 20 nm, consist mainly of an anatase crystalline phase after heat treatment at $650^{\circ}C$, since the anatase crystallites at the tube walls do not undergo transformation into rutile phase, due to the constraints imposed by the wall thickness. Among them, the medium size (ca. 8 ${\mu}m$) tubes provide the optimum conditions, irrespective of the light intensity, which is explained in terms of the correlation between the amount of photons and the adsorbed electron acceptors and their location. Photocatalytic Cr(VI) reduction leads to ca. 60% reduction of Cr(VI) even under 1 sun irradiation with the medium-sized anodized $TiO_2$ tubes, but only ca. 20% with the short- and long-sized tubes. For hydrogen evolution, tubes longer than 8 ${\mu}m$ do not exhibit better performance with any light intensity.

• 한국응용과학기술학회지
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• 제32권1호
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• pp.16-22
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• 2015

빈카마이너 L.의 알칼로이드는 HPLC의 PDA 검출기를 이용하여 측정하고 이를 표준시료인 빈카민의 자외선/가시광선 흡수 스펙트럼과 비교하여 분석하였다. 플라보노이드류를 포함하여 추출물에서 9개 이상의 화합물에 대한 자외선/가시광선 흡수 스펙트럼을 얻었다. 추출방법에 따라 에탄올 추출물과 열수 추출물을 얻고 이를 DPPH 라디칼 소거법에 의해 항산화 효과를 조사하였다. 그 결과 에탄올 추출물과 열수 추출물 모두 비교군인 케르세틴과 비타민 C 대비 약 14~15%의 항산화 효과를 보여 추출법에 상관없이 유사한 결과를 보였다.

• 분석과학
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• 제23권3호
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• pp.225-232
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• 2010

본 연구에서 종래의 졸-겔법을 사용하여 Fe-ACF/$TiO_2$ 광촉매 복합체를 제조하였고, 이들 광촉매의 분해능은 메틸렌블루 (MB) 용액의 분해에 의하여 나타내었다. 제조된 이들 복합체에 대한 입자크기, 표면구조, 결정상 및 원소분석을 BET, SEM, XRD 및 EDX에 의하여 각각 특성화 하였다. 가시광선 조건에서 분해된 MB 농도에 대한 스펙트라는 UV/Vis 분광기에 의하여 얻어 졌다. 이와 같이 얻어진 스펙트라는 MB의 제거된 농도로부터 광촉매 활성을 입증하였다. 이들 광촉매 활성은 가시광선 조건에서 복합체 광촉매 내에 존재하는 ACF, $TiO_2$ 및 Fe 사이에 강력한 시너지 반응에 의해 유도된 것으로 여겨진다.

• Journal of Photoscience
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• 제5권1호
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• pp.1-10
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• 1998

The susceptibility of chilling-resistant spinach plants. and of chilling-sensitive squash plants to photoinhibition was compared in terms of the activity of photosystem II, in relation to the deuce of fatty acid unsaturation of chloroplast membrane lipids. From thylakoid membranes of the plants. monogalactosyl diacylgtycerol, digalactosyl diacylglycerol. sulfoquinovosyt diacylglycerol, and phosphatidylglycerol were seperated as major lipid classes. It was found that the content of cis-unsaturated fatty acids of phosphatidylglycerol was greater by 32% in spinach than that in squash. When leaf disks were exposed to light at 5$\circ$C, 15$\circ$C and 25$\circ$C, photochemical efficiency of photosystem II. measured as the ratio of the variable to the maximum fluorescence of chlorophyll, declined markedly in squash plants, as compared to spinach plants. When leaf disks were exposed to strong light in the presence of lincomycin, an inhibitor of protein synthesis in chloroplasts, photoinhibition was accelerated in the two types of plants. Moreover, lincomycin treatment abolished the differences in the degree of susceptibility to strong light, which had been observed between the two types of plants. When the extent of photoinhibition of photosystem II-mediated electron transport was compared in thylakoid membranes isolated from the two types of plants, there were no differences in the degree of inactivation of photosystem II activity. However, when intact leaf disks were exposed to strong light either at 10$\circ$C or at 25$\circ$C, and then were allowed to recover either at 17$\circ$C or at 25$\circ$C in dim light. chilling-resistant plants such as spinach and pea showed marked recovery from photoinhibition, in contrast to chilling-sensitive plants, such as squash and sweet potato. whose recovery was strongly dependent on the temperature. These findings are discussed in relation to the unsaturation of fatty acids in membrane phosphatidylglycerol. It appears that fatty acid unsaturation of membrane lipids accelerates the recovery of photosystem H from photoinhibition, without affecting the photo-induced inactivation process of photosystem II associated with photoinhibition.

• Bulletin of the Korean Chemical Society
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• 제35권4호
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• pp.1182-1190
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• 2014

$Cd_{1-x}Zn_xS$-sensitized $K_4Nb_6O_{17}$ composite photocatalysts (designated $Cd_{1-x}Zn_xS/K_4Nb_6O_{17}$) were prepared via a simple deposition-precipitation method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDS), $N_2$ sorption, ultraviolet-visible light diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence measurements (PL), and X-ray photoelectron spectroscopy (XPS). The $Cd_{0.8}Zn_{0.2}S$ particles were scattered on the surface of $K_4Nb_6O_{17}$, and had a relatively uniform size distribution around 50 nm. The absorption edge of $K_4Nb_6O_{17}$ was shifted to the visible light region and the recombination of photo-generated electrons and holes suppressed after $Cd_{0.8}Zn_{0.2}S$ loading. The $Cd_{0.8}Zn_{0.2}S$(25 wt %)/$K_4Nb_6O_{17}$ composite possessed the highest photocatalytic activity for hydrogen production under visible light irradiation, evolving 8.278 mmol/g in 3 h. Recyclability tests were performed, and the composite photocatalysts were found to be fairly stable. The mechanism of charge separation between the photogenerated electrons and holes at the $Cd_{0.8}Zn_{0.2}S/K_4Nb_6O_{17}$ composite was discussed.

• 한국세라믹학회지
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• 제50권4호
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• pp.251-256
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• 2013

Multiwalled carbon nanotubes (MWCNTs) modified with Pd and $TiO_2$ composite catalysts were synthesized by the sol-gel method followed by solvothermal treatment at low temperature. The chemical composition and surface structure were characterized by X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Photocatalytic recycle degradation experiments were carried out under both UV and visible light irradiation in the presence of MWCNT/$TiO_2$ and Pd-MWCNT/$TiO_2$ composites. As expected, the nanosized Pd-MWCNT/$TiO_2$ photocatalysts had enhanced activity over the non Pd treated MWCNT/$TiO_2$ material in the degradation of a rhodamine B (Rh.B) solution. An increase in photocatalytic activity was observed and attributed to an increase in the photo-absorption effect by MWCNTs and the cooperative effect of Pd and $TiO_2$ nanoparticles. According to the recycled results, the as-prepared Pd-MWCNT/$TiO_2$ sample had a good effect on it.

• 공업화학
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• 제22권5호
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• pp.545-550
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• 2011

바이오 분자의 고정 링커로 전기전도도가 높은 방향족 공액구조의 4-(2-(4-(acetylthio)phenyl)ethynyl)benzoic acid (APBA) 분자를 합성한 후, APBA 자기조립 단분자막을 제작하였다. 제작한 APBA 자기조립 단분자막의 구조를 분석하였고, 페로센으로 고정화시킨 APBA의 자기조립 단분자막의 전기화학적 특성을 조사하였다. 부탄티올 단분자막에 APBA를 삽입시켜 혼합 단분자막을 제조하여 XPS로 금 기판에 대한 혼합 단분자막의 수직 배향성을 조사하였다. 또한, APBA 혼합 시간에 따른 APBA와 부탄티올(BT) 혼합 단분자막에 페로센을 고정화하여 전기화학적 산화 환원 특성을 조사하였다. 혼합 단분자막의 전기화학적 활성은 혼합 시간의 증가에 따라 증가하였고, 부탄티올 단분자막 기판을 APBA 용액에 36 h 침지시켰을 때 가장 높은 페로센 분자의 산화 환원 전류값을 얻었다.

• 한방안이비인후피부과학회지
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• 제35권4호
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• pp.200-208
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• 2022

만성 두드러기 환자에게 조위승기탕(調胃承氣湯) 가감방(加減方) 투여가 증상 호전에 효과를 나타냄을 확인할 수 있었다. 본 환자는 변비 및 상열감과 함께 구진성 두드러기와 중증도 이상의 소양감을 호소하였고, 항히스타민제와 외용 양약 제제에 반응하지 않았지만 한약 복용 후 피부 소양감 및 병변의 개선을 보였다. 조위승기탕(調胃承氣湯)의 완하(緩下)작용이 적열(積熱)을 풀어 피부 질환에 유효한 효과를 갖는 것으로 보이고, 이로써 만성 두드러기에서 치료 효과를 발휘한 것으로 사료된다.