• 한국미생물·생명공학회지
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• 제15권2호
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• pp.122-128
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• 1987

Candida rugosa와 Rhizopus arrhizus 리파제를 photocrosslinkable resin prepolymer에 고정화시켜서 이소옥탄을 유기용매로 사용한 이상계를 이용해서 유지분해 및 에스테르교환 반응을 보고자했다. Dioctylsulfosuccinate가 가장 좋은 surfactant였다. 소수성 젤인 ENTP-3000에 고정된 리파제가 좋은 활성을 나타냈고 친수성 젤인 ENT-4000에 고정된 리파제가 유기용매에 대해 안정했다. 고정화 matrix의 소수성이 증가될수록Vm(app)는 증가되었으나 Km(app)는 거의 일정했다. 리파제의 최적 pH는 소수성 젤인 ENTP-3000에 고정된 경우 C. rugosa와 R. arrhizus 리파제에 대해서 각각 6.0과 6.5였으나, 친수성 젤에 고정된 리파제는 짧은 시간 반응에는 pH에 크게 영향을 받지 않았으나 긴 시간 동안 반응시킬 때는 역시 pH6.0과 6.5에서 각각 C. rugosa와 R. arrhizus 리파제가 높은 양의 지방산을 분해시켰다. 리파제를 entrapment 시키면 열안정성이 증가됨을 알 수 있었다.

• Toxicological Research
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• 제34권1호
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• pp.31-39
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• 2018

The objective of this study was to evaluate the antioxidant and anti-aging effects of marigold methanol extract (MGME) in human dermal fibroblasts. Total polyphenolic and flavonoid contents in MGME were 74.8 mg TAE (tannic acid equivalent)/g and 85.6 mg RE (rutin equivalent)/g, respectively. MGME ($500{\mu}g/mL$) increased 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging, and superoxide dismutase (SOD)-like antioxidant activities by 36.5, 54.7, and 14.8%, respectively, compared with the control. At $1,000{\mu}g/mL$, these activities increased by 63.7, 70.6, and 20.6%, respectively. MGME ($100{\mu}g/mL$) significantly increased the synthesis of type 1 procollagen by 83.7% compared with control treatment. It also significantly decreased Matrix Metalloproteinase-2 (MMP-2) activity and MMP-1 mRNA expression by 36.5% and 69.5%, respectively; however, it significantly increased laminin-5 mRNA expression by 181.2%. These findings suggest that MGME could protect human skin against photo-aging by attenuating oxidative damage, suppressing MMP expression and/or activity as well as by stimulating collagen synthesis.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.66-66
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• 2018

Light fermentation has been conducted under different light conditions such as normal dark light, white light, and light emitting diodes (LEDs) various color (blue, green, red, white on blueberry powder with fermenting bacteria Bacillus subtilis (B2). The bacteria B2 was isolated and identified by 16S rRNA sequencing method. RYRP biologically converted to secondary metabolites through light fermentation in the presence of Bacillus subtilis, the bacteria actively involved in bioconversion process. LEDs fermentation to enhance the production of phenolic content while comparing to normal dark and white light. Among the different color LEDs, blue LEDs mediated fermentation showed higher amount of total phenolic and flavonoid content. Then blue LEDs mediated fermented compound were characterized by FTIR and GC-MS, subsequently the compound was analyzed antioxidant activity tests and the antioxidant activity exhibited higher. This is the first study to demonstrate that B. subtilis-LEDs mediated fermentation is useful for facilitating phenolic compound production and enhancing antioxidant activity, which may have greater application fermentation fields.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권5호
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• pp.1236-1251
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• 2013

Sharing geo-tagged photos has been a hot social activity in the daily life because these photos not only contain geo information but also indicate people's hobbies, intention and mobility patterns. However, the present raw geo-tagged photo routes cannot provide information as enough as complete GPS trajectories due to the defects hidden in them. This paper mainly aims at analyzing the large amounts of geo-tagged photos and proposing a novel travel route restoring method. In our approach we first propose an Interest Measure Ratio to rank the hot spots based on density-based spatial clustering arithmetic. Then we apply the Hidden Semi-Markov model and Mean Value method to demonstrate migration discipline in the hot spots and restore the significant region sequence into complete GPS trajectory. At the end of the paper, a novel experiment method is designed to demonstrate that the approach is feasible in restoring route, and there is a good performance.

• 한국세라믹학회지
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• 제46권6호
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• pp.561-567
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• 2009

The Fe-ACF/$TiO_2$ composites were prepared by a sol-gel method and were characterized by nitrogen adsorption, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Energy Dispersive X-ray (EDX). The Fe-ACF/$TiO_2$ composites were developed for the decomposition of organic dyes by using a UV lamp. The decomposition effect was investigated under various conditions, such as three selected non-biodegradable organic dyes like Methylene Blue (MB), Methyl Orange (MO), Rhodamine B (Rh.B), and in the presence of Fe and hydrogen peroxide ($H_2O_2$). The photocatalytic activity was derived from possible combination effects, such as (1) adsorption of ACF, (2) generation of electron/hole by $TiO_2$, (3) photo-Fenton reaction of Fe, and (4) oxidation of $Fe^{2+}\;to\;Fe^{3+}\;by\;H_2O_2$.

• 한국태양에너지학회 논문집
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• 제23권4호
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• pp.29-35
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• 2003

We studied the water splitting into $H_2$ and $O_2$ using two different semiconductor photo catalysts and redox mediator, mimicking the Z-scheme mechanism of the photosynthesis, $H_2$ evolution took place on a Pt-$SrTiO_2$ (Cr-Ta doped) photocatalyst using $I^-$ electron donor under the visible light irradiation. The Pt-$WO_3$ photocatalyst showed an excellent activity of the $O_2$ evolution using $IO_3^-$ electron acceptor under visible light. $H_2$ and $O_2$ gases evolved in the stoichiometric ratio($H_2/O_2$=2) under visible light using a mixture of the Pt-$WO_3$ and Pt-$SrTiO_3$ (Cr-Ta doped) suspended in NaI aqueous solution. We proposed a two-step photo-excitation mechanism using redox mediator under the visible irradiation.

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.49-52
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• 2007

Prodigiosin (1) is the parent member of a class of polypyrrole natural products that exhibit promising anticancer activities. They can facilitate copper-promoted oxidative DNA damage by binding to copper ions, and this activity is thought to represent their mechanism of cytotoxicity in the dark. They also possess photoinduced cytotoxicity, although 1 is too toxic in the dark to be used effectively for the treatment of cancer by photodynamic therapies. To circumvent dark toxicity by prodigiosins, the semi-synthetic analogue 2, in which the N-pyrrolic atoms of 1 are methylated to block copper coordination, and the synthetic phenyl analogues 3 and 4, which lack the copper-coordinating A-pyrrole ring of 1, were tested for their ability to inhibit colony formation of HL-60 cancer cells in the absence and presence of visible light (λ > 495 nm). Our results show that 2-4 lack cytotoxicity in the dark, but are able to inhibit colony formation of HL-60 cells following irradiation for 30 min. The synthetic derivative 4 exhibits photo-induced cytotoxicity similar to that of the natural product 1, demonstrating the potential use of prodigiosin-based compounds for treatment of cancers following irradiation with visible light.

• Environmental Analysis Health and Toxicology
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• 제22권3호
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• pp.189-196
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• 2007

[ $TiO_2$ ] is widely used because it is non-toxic. Recently, however, nanometer size $TiO_2$ particles (P-25) have been produced and used to increase the photo catalysis efficiency. Nanometer-sized $TiO_2$ is efficient, but due to its small size ($20{\sim}30\;nm$), it can flow into ecosystems and into cells. Thus, it may affect human health. Additionally, $TiO_2$ can produce a second contaminant, OH-radical, which is a health risk for all living organisms during photo degradation reaction. Hence, when nanometer-sized $TiO_2$ flows into natural streams and attaches to living organisms, it will create health risks. We investigated the biological toxicity of this condition in zebrafish embryos. We observed abnormal morphology, hatching rate, and measured the catalase activity to determine anti-oxidation at 100 post fertilization hours. Zebrafish were somewhat affected by $TiO_2$ nanometer sized particles under UV-A (a condition similar to sunlight). Powdered $TiO_2$ is toxic to the zebrafish fly. Even without light, $TiO_2$ particles attached to embryos and flies, having an effect on both.

• Advances in environmental research
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• 제5권1호
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• pp.61-77
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• 2016

$NanoTiO_2$ was synthesized by ultrasonication assisted sol-gel process and subjected to iron doping and carbon-iron codoping. The synthesized catalysts were characterized by XRD, HR-SEM, EDX, UV-Vis absorption spectroscopy and BET specific surface area analysis. The average crystallite size of pure $TiO_2$ was in the range of 30 - 33 nm, and that of Fe-$TiO_2$ and C-Fe $TiO_2$ was in the range of 7 - 13 nm respectively. The specific surface area of the iron doped and carbon-iron codoped nanoparticles was around $105m^2/g$ and $91m^2/g$ respectively. The coupled semiconductor photo-Fenton's activity of the synthesized catalysts was evaluated by the degradation of a cationic dye (C.I. Basic blue 9) and an anionic dye (C.I. Acid orange 52) with concurrent investigation on the operating variables such as pH, catalyst dosage, oxidant concentration and initial pollutant concentration. The most efficient C-Fe codoped catalyst was found to effectively destruct synthetic dyes and potentially treat real textile effluent achieving 93.4% of COD removal under minimal solar intensity (35-40 kiloLUX). This reveals the practical applicability of the process for the treatment of real wastewater in both high and low insolation regimes.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.135-141
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• 2023

Protection of skin cells from chronic infrared-A (IRA) irradiation is crucial for anti-photoaging of the skin. In this study, we investigated the protective activity of Rg3(S) and Rg3(S)-incorporated anionic soybean lecithin liposomes (Rg3/Lipo) with a size of approximately 150 nm against IRA-induced photodamage in human fibroblasts. The formulated Rg3/Lipo showed increased solubility in aqueous solution up to a concentration of 200 ㎍/ml, compared to free Rg3(S). In addition, Rg3/Lipo exhibited superior colloidal stability in aqueous solutions and biocompatibility for normal human dermal fibroblasts (NHDFs). After repeated IRA irradiation on NHDFs, elevated levels of cellular and mitochondrial reactive oxygen species (ROS) were greatly reduced by Rg3(S) and Rg3/Lipo. In addition, cells treated with Rg3/Lipo exhibited noticeably reduced apoptotic signals following IRA irradiation compared to untreated cells. Thus, considering aqueous solubility and cellular responses, Rg3/Lipo could serve as a promising infrared protector for healthy aging of skin cells.