• Rapid Communication in Photoscience
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• 제2권2호
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• pp.39-41
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• 2013

It is interesting to introduce viologen moiety into photoactive compounds such as porphyrin and anthracene in the study of supramolecular system such as pseudorotaxanes. For the construction of photoactive pseudorotaxane based on porphyrin-viologen-anthracene triad or its zinc derivative threaded with bis-p-phenylene-34-crown-10 macrocycle, porphyrin-viologen-anthracene triad 1 and its zinc derivative zinc porphyrin-viologen-anthracene triad 2 were prepared and their absorption and fluorescence spectral properties were measured.

• 대한화학회지
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• 제56권2호
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• pp.185-187
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• 2012

• 대한환경공학회지
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• 제34권1호
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• pp.63-71
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• 2012

현대산업에서 나노기술의 이용성이 증가되면서 나노물질이 가질 수 있는 잠재적인 위해성에 대한 관심이 증가되고 있는 추세이다. 나노물질은 다양한 경로를 통해 환경으로 유출되고 있으며, 수생태계로 유출된 나노물질은 태양광에 포함된 자외선에 노출될 개연성이 높다. 광반응성 나노물질은 광활성 조건에서 생태독성이 변화할 가능성이 있는 것으로 알려져 있다. 본 연구에서는 광반응성 나노물질이 생태계에서 자외선에 노출되었을 때 유발될 수 있는 생태독성 변화에 대한 연구동향을 파악하고자, 수서 및 토양생물을 대상으로 가용한 모든 자료를 조사하여 분석하였다. 본 연구에서 조사된 광반응성 나노물질은 zinc oxide, titanium dioxide, 그리고 fullerene이었으며, 미생물, 지렁이, 토양선충, 조류, 그리고 어류 등을 대상으로 한 나노물질 생태독성연구를 분석하였다. 그 결과, 자외선에 노출된 나노물질의 광독성영향에 대한 연구는 현재까지 매우 부족한 상태로, 현재까지 발표된 나노물질에 대한 광독성 연구는 8개였고, 일부 연구에서는 광반응성 나노물질의 광이온화와 나노물질로부터 용출된 이온독성을 함께 제시하였다. 광반응성 나노물질은 생체 내에서 산소활성종 생성을 유발하고 산화스트레스를 증가시키는 것으로 확인되었다.

• 한국전기전자재료학회논문지
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• 제35권6호
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• pp.581-593
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• 2022

As energy depletion and environmental pollution problems are intensified, research has been conducted actively on alternative energy sources, an eco-friendly and continuous available energy conversion system. So has been organic solar cells whose efficiency is improved to 18.32%. The photoactive layer inside the solar cell is composed of a donor and a acceptor, and the combination of materials capable of effectively exchanging electrons greatly affects the efficiency of the organic solar cell. Accordingly, various researches have been conducted to improve the efficiency, and the maximum efficiency could be achieved by a solar cell with high carrier generation and low charge recombination characteristics through the introduction of a non-fullerene acceptor and material reconstruction. Organic solar cells are still difficult to commercialize due to their efficiency limitations and light stability, but if a photoactive layer consisting of a donor capable of efficiently absorbing long-wavelength light and an acceptor capable of forming an appropriate energy level is designed, the efficiency of the organic solar cell will reach 20%.

• Bulletin of the Korean Chemical Society
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• 제25권11호
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• pp.1676-1680
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• 2004

We demonstrate that wide-angle X-ray scattering pattern from photoactive yellow protein (PYP) in solution using a high flux third generation synchrotron X-ray source reflects not only the overall structure, but also fine structures of the protein. X-ray scattering data from PYP in solution have been collected in q ranges from 0.02 ${\AA}^{-1}$ to 2.8 ${\AA}^{-1}$. These data are sensitive to the protein structure and consistent with the calculation based on known crystallographic atomic coordinates. Theoretical scattering patterns were also calculated for the intermediates during the photocycle of PYP to estimate the feasibility of time-resolved wide-angle X-ray scattering experiments on such proteins. These results demonstrate the possibility of using the wide-angle solution X-ray scattering as a quantitative monitor of photo-induced structural changes in PYP.

• Journal of Photoscience
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• 제9권2호
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• pp.1-4
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• 2002

Hula-twist is a volume-conserving photoisomerization reaction mechanism postulated in 1985 to account for the rapid photoisomerization of the retinyl chromophore in rhodopsin. The requisite stereochemical consequence of simultaneous isomerization of a double bond and an adjacent single bond has recently been demonstrated in isomerization of pre-vitamin D in an organic glass and by many other examples of organic systems already reported in the literature This paper reports the consequence in applying the mechanism to the primary photochemical process of several photosensitive biopigments: bilirubin, photoactive yellow protein, bacteriorhodopsin and rhodopsin. It is shown that the anchored nature of the chromophores must first be taken into consideration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2007년도 제32회 학술대회 초록집
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• pp.46-46
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• 2007

• Journal of Photoscience
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• 제9권2호
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• pp.134-137
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• 2002

PYP consists of a water-soluble apoprotein and 4-hydroxycinnamyl chromophore bound to Cys69 via thiolester linkage, Upon absorption of a photon, the photocycle is initiated, leading to formation of several photo-intermediates. Among them, M intermediate is important to understand the signal transduction mechanism of PYP, because it is a putative signaling state. As well known, the dynamics of a protein is closely correlated with the occurrence of its function. Here we report the results of IO ns molecular dynamics (MD) simulation for the M intermediate in aqueous solution and discuss the characteristic feature of this state from a viewpoint of structural fluctuation.

• Advances in materials Research
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• 제2권1호
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• pp.65-75
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• 2013

Heterogeneous photocatalysis is a rapidly developing field in environmental engineering. It has a great potential to cope with the increasing pollution in the air. The addition of a photocatalyst to ordinary building materials such as tiles, concrete, paints, creates environmental friendly materials by which air pollution or pollution of the surface itself can be controlled and diminished. This work reports the results of the laboratory research, especially carried out towards air purifying action and self-cleaning measurements. In particular the research was focused on the study of the photocatalytic behavior of industrially prepared tiles produced starting from commercial micro-sized $TiO_2$. Air purification action has been investigated through NOx degradation tests. On the contrary, the degradation of pollution at the surface, also called as self-cleaning action, is verified by the degradation of two different organic dyes: Rhodamine B (red color) and Metanil yellow (yellow).

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.64-66
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• 2005

Photosynthetic microbes possess a wealth of photoactive proteins including chlorophyll-based pigments, phototropin-related blue light receptors, phytochromes, and cryptochromes. Surprisingly, recent genome sequencing projects discovered additional photoactive proteins, retinal-based rhodopsins, in cyanobacterial and algal genera. Most of these newly found rhodopsin genes and retinal synthase have not been expressed and their functions are unknown. Analysis of the Anabaena and Chlamyrhodopsin with retinal synthase revealed that they have sensory functions, which, based on our work with haloarchaeal rhodopsins, may use a variety of signaling mechanisms. Anabaena rhodopsin is believed to be sensory, shown to interact with a soluble transducer and the putative function is either chromatic adaptation or circadian rhythm. Chlamydomonas rhodopsins are involved in phototaxis and photophobic responses based on electrical measurements by RNAi experiment. In order to analyze the protein, we developed a sensory rhodopsin expression system in E. coli. The opsin in E. coil bound endogenous all-trans retinal to form a pigment and can be observed on the plate. Using this system we could identify retinal synthase in Anabaena PCC 7120. We conclude that Anabaena D475 dioxygenase functions as a retinal synthase to the Anabaena rhodopsin in the cell.