• Polymer Science and Technology
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• v.24 no.3
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• pp.254-260
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• 2013

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.797-805
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• 2012

Contribution of immobilized media with bacteria to the odor removal was evaluated in a lab scale bio-filter compared to that with sponge or ceramic media without the immobilized bacteria. Candida tropicalis for volatile organic compounds and ammonium oxidizing bacteria (AOB) for inorganic compounds were used as seeds in lab-scale bio-reactors. Three different type of media in the bio-reactors that immobilized bioreactor (IBR), sponge bioreactor (SBR), and ceramic bioreactor (CBR) were examined, respectively. An empty bed contact time (EBCT) of the bio-filters was fixed as 60 seconds, and the inlet concentration of toluene was changed from 20 ppm to 200 ppm to observe the removal efficiency depending on the concentrations. As a result, the maximum elimination capacities of IBR, SBR, and CBR were 166 $g/m^3/hr$, 138 $g/m^3/hr$, and 138 $g/m^3/hr$, respectively. In addition, toluene as an organic compound and ammonia as an inorganic compound were applied together with different inlet concentrations varied from 80 ppm to 250 ppm of toluene and from 2.5 ppm to 40 ppm of ammonia. The toluene maximum elimination capacities in IBR, SBR, and CBR were 97.4 $g/m^3/hr$, 59.5 $g/m^3/hr$, and 81.9 $g/m^3/hr$, respectively. The ammonia maximum elimination capacities were reached as 7.2 $g/m^3/hr$ in IBR, 6.6 $g/m^3/hr$ in SBR, and 7.0 $g/m^3/hr$ in CBR.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.232-243
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• 2010

In this paper, various physiological signals of humans were measured and analyzed to inference their psychological state and biological information, and Bio-Signal Context aware system (BSC), which recognizes the current context of its users as well as the information of exterior environment and offers the service appropriate for them, was designed and implemented. The BSC extracts and analyzes the features from bio-signals, such as the measured electroencephalogram (EEG), electrocardiogram (ECG), and galvanic skin response (GSR), with its different sensors, has the input of the analyzed results, and discriminates four psychological states of rest, concentration, tension and melancholy. In addition to the results of the discriminated psychological states, the information of biological condition analyzed from the user's bio-signals, for example, heart rate variability (HRV), Galvanic skin response (GSR) and body temperature, and the information of external environment related to the user's are collected to offer the service fit for the user's present biological condition by inferring and recognizing the user's present situation.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.651-654
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• 2005

Analysis of extra- and intra- cellular metabolites is very important to study cell metabolish. Intracellular amino acids in yeast are of great interest as precursors of desired products in biomass production of the feed industries and the production of glutamate. In this study, the fermentations of P. pastoris X-33 and KM71H were carried out in shake flasks. After centrifugation, the harvested cells were mechanically disrupted by using glass bead. The supernatants were used to analyze intracellular amino acid by HPLC system. For HPLC analysis, Resolve C18 column was used with Fluorescence detector. The OPA(o-phthalaldehyde) derivation reaction was employed for analysing amino acids at 30 $^{\circ}C$, 1 ml/min and gradient mode. The concentration of intracellular protein was measured by spectrophotometer.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.54-59
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• 2006

Biophotonic sensors based on polymer waveguide with Bragg reflection grating are demonstrated in this work. Waveguide Bragg reflectors were designed by using the effective index method and the transmission matrix method. The grating pattern was formed by exposing the laser interference pattern on a photoresist. On top of the inverted rib waveguide, the Bragg reflection grating was inscribed by the O2 plasma etching. In order to perform the bio-molecule detection experiment, a calixarene molecule was self-assembled on top of thin Au film deposited on the waveguide Bragg reflector. To measure the response of the sensor, several PBS solutions with different concentrations of potassium ion from 1 pM to $100\;{\mu}M$ were dropped on the sensor surface. The shift of Bragg reflection wavelength was observed from the fabricated sensor device, which was proportional to the concentration of potassium ion ranging from 1 pM to 108 pM.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.54-60
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• 2006

In this paper, we describe a bio-fluidic device for adaptive sample pretreatment, in order to optimize the conditions under which absorbance assays can be conducted. This device can be successfully applied to the measurement of Escherichia coli (E. coli) concentrations using adaptive dilution, with which the dilution ratio can be adjusted during the dilution. Although many attempts have been previously made to miniaturize complex biochemical analyses at the chip scale, very few sample pretreatment processes have actually been miniaturized or automated at this point. Due to the lack of currently available on-chip pretreatments, analytical instruments tend to suffer from a limited range of analysis. This occasionally hinders the direct and quantitative analysis of specific analyses obtained from real samples. In order to overcome these issues, we exploit two novel strategies: dilution with a programmable ratio, and to-and-fro mixing. The bio-fluidic device consists of a rectangular chamber constructed of poly(dimethylsiloxane) (PDMS). This chamber has four openings, an inlet, an outlet, an air control, and an air vent. Each of the dilution cycles is comprised of four steps: detection, liquid drain, buffer injection, and to-and-fro mixing. When using adaptive sample pretreatment, the range in which E. coli concentrations can be measured is broadened, to an optical density (O.D.) range of $0.3{\sim}30$. This device may prove useful in the on-line monitoring of cell concentrations, in both fermenter and aqueous environments.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3567-3572
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• 2010

Black pine barks from the southern region of Korea were extracted using pressurized hot water and the water soluble extracts were then separated in a stepwise fashion using a variety of solvents, column chromatography (CC), thin layer chromatography (TLC), and high pressure liquid chromatography (HPLC). The antioxidant activities of each fraction and the active compounds were determined based on the radical scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH), reductive potential of ferric ion, and total phenol contents. A DPPH test showed that the half maximal effective concentration ($EC_{50}$ value : $6.59{\pm}0.31\;{\mu}g/mL$) of the ethyl acetate fraction (ca. 0.67%) was almost the same as that of the control compounds and inversely proportional to the value of the total phenol contents. The cell viability of the water extracts was confirmed by methyl thiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT) with enzyme linked immune sorbent assay (ELISA). Catechin, epicatechin, quercetin and ferulic acid were isolated from the ethyl acetate fraction as active compounds and identified by nuclear magnetic resonance. The antioxidant activity as value of DPPH of each of the separated compounds was lower than the ethyl acetate fraction, and ferulic acid was the lowest among these compounds.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1067-1076
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• 2016

The gene encoding lipase (Lip98) from Aeromicrobium sp. SCSIO 25071 was cloned and functionally expressed in Escherichia coli. Lip98 amino acid sequence shares the highest (49%) identity to Rhodococcus jostii RHA1 lipase and contains a novel motif (GHSEG), which is different from other clusters in the lipase superfamily. The recombinant lipase was purified to homogeneity with Ni-NTA affinity chromatography. Lip98 showed an apparent molecular mass of 30 kDa on SDS gel. The optimal temperature and pH value for enzymatic activity were recorded at 30℃ and 7.5, respectively. Lip98 exhibited high activity at low temperatures with 35% maximum activity at 0℃ and good stability at temperatures below 35℃. Its calculated activation energy was 4.12 kcal/mol at the low temperature range of 15-30℃. Its activity was slightly affected by some metal ions such as K⁺, Ca²⁺, and Na⁺. The activity of Lip98 was increased by various organic solvents such as DMSO, ethanol, acetone, and hexane with the concentration of 30% (v/v) and retained more than 30% residual activity in neat organic solvent. The unique characteristics of Lip98 imply that it is a promising candidate for industrial application as a nonaqueous biocatalyst and food additive.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.209-213
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• 2014

The anti-melanogenic substance was isolated from the root of Angelica gigas Nakai by silica gel column chromatography, preparative HPLC and TLC. As a result of the structure analysis by mass, $^1H$-NMR, and $^{13}C$-NMR spectrometry, the compound was identified as demethylsuberosin. Demethylsuberosin reduced melanin contents of B16F1 melanoma cells in a dose-dependent manner and decreased to about 74% at a concentration $5{\mu}g/ml$. Demethylsuberosin inhibited the expression in microphthalmia associated transcription factor (MITF), tyrosinase, tyrosinase related protein-1 (TRP-1), and tyrosinase related protein-2 (TRP-2) in melanocytes. These results suggest that the whitening activity of demethylsuberosin may be due to the inhibition of the melanin synthesis by down-regulation of MITF, tyrosinase, TRP-1 and TRP-2 expression. Thus, our results provide evidence that demethylsuberosin might be useful as a potential skin-whitening agent.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.6
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• pp.666-670
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• 2015

Competition among anion species in solution for same sorption sites and soil surface can be of major significance in determining the effective mobility of any potentially adsorbing species. Major soil anion species include $OH^-$, $F^-$, $Cl^-$, $HCO_3{^-}$, $CO_3{^-}$, $NO_3{^-}$, $SO_4{^{2-}}$, and $PO_4{^{3-}}$. And some micro nutrients such as boron and molybdenum exist as $H_2BO_3{^-}$ and $MoO_4{^{2-}}$, as do some heavy metals such as chrome and arsenic as $CrO_4{^{2-}}$ and $HAsO_4{^{2-}}$. Pesticides such as 2,4,5-T and 2,4-D also exist as anions. Many anion species are retained by more complex mechanisms than the simple electrostatic attractions involved in most cation adsorption reactions. In binary system composed of two anions, the adsorption of one anion is influenced by the other anion due to the competition for the available and limited binding sites in soil constituents. The specifically adsorbed anions may compete more effectively for sorption sites than that of nonspecifically adsorbed anion. In this study, we aim to evaluate the mathematical models to determine the magnitude of concentration variations in adsorption due to competitive interactions between anions introduced to a system in binary mixtures.