• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.242-248
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• 1979

To detect proper lytic assay conditions of the crude zumolyase from Arthrobacter luteus, effets of the various factors involved in the lytic system of Sacchromyces sake cultured with shaking in the malt extracts medium were investigated. The results are summarized as follows : 1. The susceptibilities of viable cells of S. sake from logarithmic growth phase to the lytic enzmye were much greater than those of the cells in lag and stationary phases. The cells cultured for 18 hr were the most susceptible to the enzyme. 2. Lytic activity of the enzyme toward the viable cells of S. sake was very low. It was, however, enhanced 4 folds of more by the pretreatment of the cells with 0.05 M sodium sulfite. 3. Lytic activity of the enzyme toward commercial baker's yeast cells was negligible, and the effect of sodium sulfite on the lysis of the cells also was nothing but a little. 4. The lyophilized cells of the baker's yeast showed more susceptibility to the lytic enzyme than viable cells of the yeast. No definite effect of sodium sulfite on the lysis of the lyophilized cells, however, was observed either baker's yeast of S. sake. 5. It appeared that the relationship between the reaction rate and the enzyme concentration on the lysis of the yeast cell walls followed enzyme kinetic theory, but one between the reaction rate and concentration of the yeast cells as substrates showed different pattern from that in enzyme kinetic theory. 6. After the preparation of crude zymolyase was kept at $7^[\circ}C$ for 10 days in the 0.05 M phosphate buffer, pH 7.5, the remainning lytic activity was about 80 %.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1133-1140
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• 2006

Human HtrA1 (High temperature requirement protein A1) is a homologue of the E. coli periplasmic serine protease HtrA. A recent study has demonstrated that HtrA1 is a serine protease involved in processing of insulin like growth factor binding protein (ICFBP), indicating that it serves as an important regulator of IGF activity. Additionally, several lines of evidence suggest a striking correlation between proteolytic activity of HtrA1 serine protease and the pathogenesis of several diseases; however, physiological roles of HtrA1 remain to be elucidated. We used the pGEX bacterial expression system to develop a simple and rapid method for purifying HtrA1, and the recombinant HtrA1 protein was utilized to investigate the optimal conditions in executing its proteolytic activity. The proteolytically active HtrA1 was purified to approximately 85% purity, although the yield of the recombinant HtrA1 protein was slightly low $460{\mu}g$ for 1 liter E. coli culture). Using in vitro endoproteolytic cleavage assay, we identified that the HtrA1 serine protease activity was dependent on the enzyme concentration and the incubation time and that the best reaction temperature was $42^{\circ}C$ instead of $37^{\circ}C$. We arbitrary defined one unit of proteolytic activity of the HtrA1 serine protease as 200nM of HtrA1 that cleaves half of $5{\mu}M\;of\;{\beta}-casein$ during 3 hr incubation at $37^{\circ}C$. Our study provides a method for generating useful reagents to investigate the molecular mechanisms by which HtrA1 serine protease activity contributes in regulating its physiological function and to identify natural substrates of HtrA1.

• Journal of Life Science
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• v.20 no.7
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• pp.1107-1112
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• 2010

In this study, the stable maintenance of bioactivity in alkaline ionized water (AIW) and antibacterial effects of AIW were evaluated to confirm benefits of AIW. As controls, purified water (PW) and tap drinking water (DW) were used. The pH and ORP (oxidation-reduction potential) of AIW, PW and DW used were 9.5 and 120 mV, 7.2 and 144 mV, and 7.3 and 564 mV, respectively. High level of minerals was observed in DW (DW>AIW>PW of mineral contents). Concentrations of $Ca^{++}$ and $Na^+$ in DW were 14.5, and 8.4 mg/l, respectively, while no $Ca^{++}$, $Mg^{++}$, $K^+$, and $Na^+$ were detected in PW. Evaluation of antioxidant activities for AIW, PW and DW showed that the waters did not act as antioxidants. However, the DPPH (1,1-diphenyl-2-picryl hydrazyl) or superoxide radical scavenging activities or reducing power of vitamin C were stably maintained in AIW and PW, though not in DW, against heat treatment ($60^{\circ}C$) or vigorous shaking (120 rpm) at $37^{\circ}C$. Similarly, after aspirin treatment at $60^{\circ}C$ for 1 hr, the antithrombosis activity in PW and AIW was 62.6% and 55.3%, while that of DW was 52.1%. Furthermore, cell growth analysis and viable cell count of Escherichia coli H7:O157 in PW, AIW and DW showed that AIW and DW, not DW, have antibacterial activities. Our results suggest that the state of water, for example pH, ORP and mineral contents of water, should be considered in medicine or food industries, and that AIW has high potential for utilization in various fields.

• Journal of Life Science
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• v.24 no.6
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• pp.686-693
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• 2014

Restricted supply of nutrients may affect genes at the molecular level as well as physiological functions. Understanding the cellular responses during starvation is necessary for developing strategies to reduce damage caused by starvation stress. After 1 h of starvation, Got1 gene expression was increased but its expression returned to the normal state after 24 h. Mat1 gene expression continuously increased with starvation from 1 h until 24 hr. Rats starved for 1-3 days showed significant changes in expression of the Got1 and Mat1 genes, which were significantly reduced in the cerebral cortex and cerebellum. In the lung, gene expression was increased by starvation for 1-2 days but decreased on the third day. No differences were observed in gene expression in the heart. Strong Got1 lung gene expression was seen in the starvation group one day after restoration of the food supply. Muscle mass was significantly reduced at the start of starvation and remained the same after two days of starvation and one day after the food supply was restored. The Mat1 gene expression did not change. The Got1 was induced by NaCl and showed strong expression in the lung and the thymus, but the apparent decrease of the remaining changes were not observed in male rats. The Mat1 gene was not as sensitive as the Got1 gene to induction by NaCl. However, differences in gene induction by NaCl were evident between males and females, indicating that diet control of gene expression is associated with hormones.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.233-241
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• 2016

Experiments were carried out to quantify the topographic effects on attenuation of sunshine in complex terrain and the results are expected to help convert the coarse resolution sunshine duration information provided by the Korea Meteorological Administration (KMA) into a detailed map reflecting the terrain characteristics of mountainous watershed. Hourly shaded relief images for one year, each pixel consisting of 0 to 255 brightness value, were constructed by applying techniques of shadow modeling and skyline analysis to the 3m resolution digital elevation model for an experimental watershed on the southern slope of Mt. Jiri in Korea. By using a bimetal sunshine recorder, sunshine duration was measured at three points with different terrain conditions in the watershed from May 15, 2015 to May 14, 2016. The brightness values of the 3 corresponding pixel points on the shaded relief map were extracted and regressed to the measured sunshine duration, resulting in a brightness-sunshine duration response curve for a clear day. We devised a method to calibrate this curve equation according to sky condition categorized by cloud amount and used it to derive an empirical model for estimating sunshine duration over a complex terrain. When the performance of this model was compared with a conventional scheme for estimating sunshine duration over a horizontal plane, the estimation bias was improved remarkably and the root mean square error for daily sunshine hour was 1.7hr, which is a reduction by 37% from the conventional method. In order to apply this model to a given area, the clear-sky sunshine duration of each pixel should be produced on hourly intervals first, by driving the curve equation with the hourly shaded relief image of the area. Next, the cloud effect is corrected by 3-hourly 'sky condition' of the KMA digital forecast products. Finally, daily sunshine hour can be obtained by accumulating the hourly sunshine duration. A detailed sunshine duration distribution of 3m horizontal resolution was obtained by applying this procedure to the experimental watershed.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.289-292
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• 2008

Trisodium phosphate 12 hydrate and citric acid monohydrate mixture showed the strong anti-sticking effect on Streptococcus mutans, Streptococcus mitis, and Streptococcus salivarius, which are adhered to glass beads. Each Streptococcus species was shaking-cultured in brain heart infusion broth containing three glass beads. After 18 hr, glass beads were slightly washed into normal saline by three-pin-pointed pincette. Each three glass-beads set was put into reagent -containing tubes, which have 40 mg of bits of weighing paper for gaining brushing effect as similar as brushing one's teeth. The tubes were shaken by vortex mixer for 10 min except non-oral microbe, Streptococcus agalactiae (5 min). The samples were colony-counted by serial agar dilution method. Experiment was repeated three times for each Streptococcus species. The relative ratios of bacterial de-adherence by reagents were calculated in comparison with normal saline control. The de-adherence degree of citric acid-trisodium phosphate-saline mixture (CTS, pH 6.0) against Streptococcus mutans came to an average of 12.5 times compared with normal saline control. Trisodium-saline (TS, pH 8.4) showed the average of 7.5 times, and citric acid-saline (CS, pH 4.6) showed 6.0 times compared to the control group. The bacterial de-adherence degree against Streptococcus salivarius was each 7.2,2.6 and 2.8 times in above reagent sequence in comparison with saline control. CTS and TS showed 2.4 and 3.4 times of anti-sticking effect on Streptococcus mitis respectively, but CS had no anti-sticking effect on this bacterium. CTS, TS and CS showed 0.7, 0.6, and 0.6 times on non-oral microbe, Streptococcus agalactiae, separately compared with saline control. These results show that oral Streptococcus mutans, Streptococcus salivarius, and Streptococcus mitis, which are causative of dental caries or subacute endocarditis, may be easily removed from oral cavity by CTS mixture. It is conceivable that our experimental results will enable the development of a new conceptive toothpaste to prevent dental caries or subacute endocarditis after drawing teeth.

• Journal of the Korean earth science society
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• v.33 no.6
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• pp.469-480
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• 2012

This study was to analyze the characteristics of diurnal variation of high $PM_{2.5}$ concentration, $PM_{2.5}/PM_{10}$ concentration ratio by spatio-temporal wind system (wind speed and wind direction) for high $PM_{2.5}$ concentration (over the 24 hr environmental standard of $PM_{2.5}$, $50{\mu}g/m^3$) in the air quality observation sites (Jangrimdong: Industrial area, Jwadong: Residential area) that were measured for 3 years (2005. 12. 1-2008. 11. 30) in Busan. The observation days of high $PM_{2.5}$ concentration were 182 at Jangrimdong and 27 at Jwadong. The seasonal diurnal variation of hourly mean of high $PM_{2.5}$ concentration and of $PM_{2.5}/PM_{10}$ concentration ratio showed a similar pattern that had higher variation at dawn, and night and in the morning than in the afternoon. Durning daytime in summer at Jwadong, the $PM_{2.5}/PM_{10}$ concentration ratio increased because a secondary particulate matter, which was created by photochemical reaction, decreased the coarse particles of $PM_{10}$ more than the fine particles of $PM_{2.5}$ concentrations in ocean condition. We did an analysis of spatio-temporal wind system (wind speed range and wind direction) in each time zone. The result showed that high $PM_{2.5}$ concentration at Jangrimdong occurred due to the congestion of pollutants emissions from the industrial complex in Jangrimdong area and the transportation of pollutants from places nearby Jangrimdong. It also showed that high $PM_{2.5}$ concentration occurred at Jwadong because of a number of local residential and commercial activities that caused the congestion of pollutants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.490-495
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• 2009

This study investigated the changes of physicochemical characteristics and antioxidant activity of heated radish (Raphanus sativus L.). Raw radish was heated at various temperatures ($110{\sim}150^{\circ}C$) for 2 hr. The heated radish was extracted with 70% ethanol and then fractionated with hexane, ethyl acetate, and aqueous. Total polyphenol contents, $IC_{50}$ value of electron donating ability (EDA), and total antioxidant activity (AEAC) increased with increasing heating temperature. The maximum total polyphenol content was $256.26{\pm}9.61$ mg/100 g at $150^{\circ}C$ (control: $27.90{\pm}1.28$ mg/100 g), $IC_{50}$ value was $1.34{\pm}0.004$ mg/mL at $150^{\circ}C$ (control: $34.93{\pm}0.039$ mg/mL), and AEAC was $53.10{\pm}1.155$ mg AA eq/g at $150^{\circ}C$ (control: $6.721{\pm}0.122$ mg AA eq/g). The ethyl acetate fraction showed higher total polyphenol contents and stronger antioxidant activities than hexane and aqueous fractions. Total polyphenol content was 133.62 mg/100 g (at $140^{\circ}C$), $IC_{50}$ values of EDA and AEAC content were 0.39 mg/mL (at $150^{\circ}C$) and 183.72 mg AA eq/g (at $140^{\circ}C$), respectively.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.143-151
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• 1999

Purpose: Dermatolymphangioadenitis (DLA) is a common and serious complication of lymphedema which deteriorates lymphatic function. The purpose of this study was to assess the risk of DLA by lymphos-cintigraphy in patients with lower extremity lymphedema. Materials and Methods: The subjects were 59 edematous lower extremities of 50 patients without previous episode of DLA and 12 lower extremities of 6 controls. Whole body images were acquired 1 min and 2 hr after subcutaneous injection of 37 MBq of Tc-99m-antimony sulfide colloid into interdigital spaces of both feet before therapy for lymphedema. The lymphosintigraphic and clinical variables were compared between groups with or without occurrence of DLA during clinical follow up. Results: There were 20 episodes of DLA in 12 extremities during clinical follow-up (19 :6 months). On univariate analysis, there were significant differences in ilioinguinal lymph node uptake, uptake pattern of main lymphatic vessel, clinical stage and therapy compliance between the two groups. After multivariate analysis, only the uptake pattern of main lymphatic vessel and therapy compliance fore confirmed to be independent variables. In other words, non-visualized main lymphatic vessel and poor compliance to therapy were more frequent in extremities with subsequent occurrence of DLA. Conclusion: Lymphoscintigraphy can be used to predict the risk of DLA and may thus be helpful for determining the initial therapeutic plan in patients with lower extremity lymphedema.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.1
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• pp.100-109
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• 2012

Removal rates of $PO_4-P$ and TP in a free water surface wetland system were investigated. The system was established in 2008 on a floodplain in the middle reach of the Gwangju Stream flowing through Gwangju City. Its dimensions were 46 meters in length and 5 meters in width. Two year old Typha angustifloria L. growing in pots were planted on half of the area and Zizania latifolia Turcz on the other half in 2008. Stream water was funneled into the wetlands by gravity flow, and its effluent was discharged back into the stream. The influent volume was controlled by valves and water depth was adjusted by wires. Volume and water quality of inflow and outflow were analyzed from January to December in 2010. Inflow into the system averaged approximately $710m^3/day$ and hydraulic residence time was about 1.5 hours. Average influent and effluent $PO_4-P$ concentration were 0.144 and 0.103mg/L, respectively, and $PO_4-P$ abatement amounted to 28.6%. Influent and effluent TP concentration averaged 0.333 and 0.262mg/L, respectively, and TP retention reached to 20.7%.$PO_4-P$ removal rate(%) during plant growing season(31.448) was significantly high(p<0.001) when compared with that during plant non-growing season(25.829). TP abatement rate(%) during plant growing season(27.230) was also significantly high(p<0.001) when compared with that of the non-growing season(14.856). Major phosphorous removals in the system resulted from adsorption of phosphorous in the litter-soil layers; sedimentation of particulate phosphorous and Ca, Al, Fe bounded phosphates; and absorption of phosphorous by emergent plants. The adsorption and sedimentation occurred throughout the year, however, the absorption took place during plant growing season. This resulted in higher removals of $PO_4-P$ and TP during plant growing season.