• Korean Journal of Microbiology
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• v.5 no.1
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• pp.15-19
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• 1967

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Physiological activities such as growth rate, reproduction, endogenous and glucose respiration, photosynthetic activity and biosythesis of chlorophyll of the micro-element definition cells were measured. It generally, growth rate, respiratory and photosynthetic activities, and biosynthesis of chlorophyll of the micro-element deficient cells decreased more or less, compared with those of the normal cells. The growth of the algal cells in an iron-free medium were retarded severely with the chlorosis, and the photosynthetic activity of the cells decreased remarkably even though the low content of chlorophyll in the cells owing to the iron-deficiency is considered. Therefore, it is deduced that iron takes part in the photosynthetic process itself, possibly by its participation in the photo phosphorylation coupled with electron transport. Respiratory activity of boron-deficient cells showed the most severe decrease whereas those of the molybdenum-deficient cells showed very slight decrease in spite of severe growth retardation.

• Carbon letters
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• v.8 no.1
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• pp.6-11
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• 2007

Carbon/$TiO_2$ composites were prepared by $CCl_4$ solvent mixing method with different mixing ratios. Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the Carbon/$TiO_2$ composite series showed a good adsorptivity and photo decomposition activity. The BET surface area for the carbon layer in the sample increases to increasing with pitch contents. The SEM results present to the characterization of porous texture on the Carbon/$TiO_2$ composite and pitch distributions on the surfaces for all the materials used. From XRD data, a weak and broad carbon peak of graphene with pristine anatase peaks were observed in the X-ray diffraction patterns for the Carbon/$TiO_2$. The EDX spectra show the presence of C, O and S with strong Ti peaks. Most of these samples are richer in carbon and major Ti metal than any other elements. Finally, the excellent photocatalytic activity of Carbon/$TiO_2$ with slope relationship between relative concentration (C/$C_0$) of MB and t could be attributed to the homogeneous coated pitch on the external surface by $CCl_4$ solvent method.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.346-353
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• 2014

The chlorophyll-related compound pheophorbide a (Pa) was successively purified from an edible red seaweed, Grateloupia elliptica, using silica, octadecyl silica column chromatography and reversed phase-high-performance liquid chromatography, as well as the cell cycle inhibitory and apoptotic effects of Pa being investigated in U87MG glioblastoma cells. The Pa exhibited strong anticancer effects in the absence of direct photo-irradiation against various cancer cell lines, including U87MG, SK-OV-3, and HeLa cells. Among the cancer cells, the strongest anticancer activity of Pa exhibited on U87MG cells with $IC_{50}$ values of 2.8 ${\mu}g/ml$. In addition, Pa specifically had cytostatic activity on glioblastoma cells rather than human umbilical vein endothelial cells. Analysis of the cell cycle distribution showed that Pa induced G0/G1 arrest of U87 MG cells. In addition, arrested cells induced late apoptosis and DNA degradation under dark condition. These results suggest that Pa isolated from G. elliptica is a potential glioblastoma-specific anticancer agent without side effects on normal cells.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.164-174
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• 2018

The purpose of this work designed hybrid-structured and plasma effect photocatalyst of $Ag/In_2O_3/TiO_2/HNTs$ via sol-gel and photo-reduction methods. The structures, morphologies, optical and photoelectric performances of as-prepared photocatalysts were characterized via XRD, TEM, XPS, BET, UV-vis DRS, PL and photocurrents. The photocatalytic activity was evaluated by degradation of TC. The results showed that the hybrid-structure and plasma effect can effectively cause the multi-transfer of electrons and increase the separation rate of electron and hole pairs which obtained high photocatalytic activity. The photocatalytic degradation processes reveal that $^{\bullet}O_2{^-}$ and $h^+$ are major active species.

• Research in Community and Public Health Nursing
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• v.33 no.3
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• pp.332-339
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• 2022

Purpose: Bus drivers are at high risk of chronic diseases due to risk factors associated with poor diet, physical inactivity, high levels of sedentary behaviors, and unfavorable working environments. This study developed a mHealth program for bus drivers, and examined the effectiveness of a mHealth program for promoting physical activity among bus drivers using wearable devices and health coaching. Methods: Forty-seven workers from two bus companies were allocated to the experimental group and the control group. Participants were asked to wear a wearable device (Fitbit Charge HR) during waking hours for a day. Participants in the experimental group were provided with a Fitbit, weekly face-to-face health coaching, a mHealth workbook, and text and photo messaging for 12 weeks. The control group only received a Fitbit. Results: By week 12, there were significant differences between the experimental and control groups in exercise self-efficacy (p<.015) and daily walking steps (p<.001). Conclusion: The findings have demonstrated that the mHealth program using wearable devices and health coaching is effective for bus drivers for promoting physical activity. Based on our findings, it is recommended to encourage the mHealth program using wearable devices and health coaching for bus drivers' wellness.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.4
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• pp.132-138
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• 2023

Doped and undoped-BiVO₄ samples with different elements (Li, Mg) and amounts were synthesized with a hydrothermal method. The synthesized samples were characterized using various techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis diffusion reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) spectroscopy. Photocatalytic activity of the samples was evaluated by measuring the degradation of methyl blue (MB) under visible light irradiation. The results indicated that the incorporation of Mg and Li into BiVO₄ caused lattice distortion, the presence of surface hydroxyl groups, a narrower band gap, and a reduced recombination ratio of photo-induced electron-hole pairs. Notably, the photocatalytic activity of Mg5%-Li5% co-doped BiVO₄ sample exhibited a significant improvement compared to that of undoped BiVO₄ sample.

• Analytical Science and Technology
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• v.19 no.5
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• pp.376-382
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• 2006

In this work, pitch/activated carbon/$TiO_2$ composite were prepared by $CCl_4$ solvent method with different mixing ratios. The BET surface area of pitch/activated carbon/$TiO_2$ composite has a significantly increase with increasing activated carbon content in pitch/activated carbon/$TiO_2$ composite. The surface structure and elemental compositions of the composite were studied by SEM and EDX, respectively. The SEM results were presented to the characterization of porous texture on the pitch/activated carbon/$TiO_2$ composite. And EDX data was shown the presence of C, O, S, Ti and other elements. The structural properties of the composite were studied in XRD measurements. The $TiO_2$ crystal phases of the pitch/activated carbon/$TiO_2$ composite had lots of rutile-type structure which transforms from anatase-type with a little of anatase-type structure. The photocatalytic activities of the composite were evaluated using a photo-decomposition method under UV lamp. The pitch/activated carbon/$TiO_2$ composites were observed better photocatalytic activity than that of pristine $TiO_2$.

• Journal of the Korea Computer Graphics Society
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• v.12 no.4
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• pp.23-32
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• 2006

In recent years, since the digital camera has been popularized, so users can easily collect hundreds of photos in a single usage. Thus the managing of hundreds of digital photos is not a simple job comparing to the keeping paper photos. We know that managing and classifying a number of digital photo files are burdensome and annoying sometimes. So people hope to use an automated system for managing digital photos especially for their own purposes. The previous studies, e.g. content-based image retrieval, were focused on the clustering of general images, which it is not to be applied on digital photo clustering and classification. Recently, some specialized clustering algorithms for images clustering digital camera images were proposed. These algorithms exploit mainly the statistics of time gap between sequent photos. Though they showed a quite good result in image clustering for digital cameras, still lots of improvements are remained and unsolved. For example the current tools ignore completely the image transformation with the different focal lengths. In this paper, we present a photo considering focal length information recorded in EXIF. We propose an algorithms based on MVA(Matching Vector Analysis) for classification of digital images taken in the every day activity. Our experiment shows that our algorithm gives more than 95% success rates, which is competitive among all available methods in terms of sensitivity, specificity and flexibility.

• The Journal of Internal Korean Medicine
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• v.40 no.6
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• pp.1112-1121
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• 2019

Objectives: FDY003 is a raw material for medicine consisting of a natural product that is expected to have the advantages of low side effects and high efficacy. In this study, we predict the efficacy and the standardization of the drug by method validation of anticipated index compounds and the measurement of antioxidant activity. Methods: FDY003 is prepared by extracting and purifying 70% of ethyl alcohol (EtOH). The method validation of cordycepin and chlorogenic acid was determined by high-performance liquid chromatography-photo diode array (HPLC-PDA) and the content of FDY003 was calculated. In order to monitor the biological activity of FDY003, antioxidant activity was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric-reducing antioxidant power (FRAP). The equivalent values of antioxidants such as trolox, ascorbic acid, gallic acid, and caffeic acid were measured by ABTS and FRAP. Results: Chlorogenic acid and cordycepin were both found suitable for method validation in HPLC and FDY003 containing 9.92±0.50 and 17.97±0.27 ㎍/g, respectively. In DPPH, the electron donating ability (EDA) value of FDY003 was increased in a concentration dependent manner. FDY003 confirmed antioxidant activity by ABTS and FRAP. Conclusions: FDY003 contains certain components including cordycepin and chlorogenic acid and has antioxidant ability by various mechanisms. Therefore, it is expected that FDY003 is capable of various physiological activities including anti-cancer activity.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.185-192
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• 1987

A green house experiment was conducted to find out the acetylene reducing and $N_2$-fixing activity from photosynthetic and aerobic heterotrophic nitrogen fixing microorganisms in submerged paddy soil under different agricultural locality, soil series, soil texture, soil type, and drainage condition in which samples taken from without nitrogen treatment plot of NPK trials on 16 sites of the farmer's field. The results obtained were summarized as follows: 1. The highest acetylene reducing activity was observed at 7 days after incubation in the light condition (photo synthetic microbes+heterotrophic bacteria) while it was observed at 35 days incubation in the dark condition (heterotrophic bacteria). 2. Among the soil series, photosynthetic nitrogen fixing activity was pronounced more in Jangae, Ogcheon and Hwadong series while lower was obtained in Buyong and Daejeong series. Aerobic heterotrophic nitrogen fixing activity was high in Buyong and Daejong series. 3. Estimated amount of $N_2$-fixation from acetylene reducing activity was equivalented to 3.0 mg in light condition and 4.9 mg/100g/105 days in dark condition. 4. Among the agricultural locality, photosynthetic nitrogen fixing activity was high in rather warm southern part while heterotrophic nitrogen fixing activity was predominated more in mountainous area and Chungcheong continental. 5. Photosynthetic nitrogen fixing activity was predominated in high productive soil while aerobic heterotrophic nitrogen fixing activity was pronounced more in crose coarse sandy soil. 6. The soils properties of high photosynthetic nitrogen fixing activity were constituted of poorly or imperfectly drained clay or clay loam soil while heterotrophic nitrogen fixing activity was pronounced more in well to moderately well drained sandy or sandy loam soil.