• Korean Journal of Microbiology
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• v.52 no.4
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• pp.455-462
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• 2016

Pseudomonas aeruginosa P-5 is an unusual organism capable of synthesizing polyhydroxyalkanoates (PHAs) consisting of 3-hydroxyvalerate (3HV) and medium-chain-length (MCL) 3-hydroxyalkanoate (3HA) monomer units when C-odd alkanoic acids are fed as the sole carbon source. Evaluation of the substrate chain-length specificity of two P. aeruginosa P-5 PHA synthases ($PhaC1_{P-5}$ and $PhaC2_{P-5}$) by heterologous expression of $PhaC1_{P-5}$ and $PhaC2_{P-5}$ genes in Pseudomonas putida GPp104 revealed that $PhaC2_{P-5}$ incorporates both 3HV and MCL 3HAs into PHA, whereas $PhaC1_{P-5}$ favors only MCL 3HAs for polymerization. In order to obtain $PhaC2_{P-5}$ mutants with altered substrate specificity, site-specific mutagenesis for $PhaC2_{P-5}$ was conducted. Amino acid substitutions of $PhaC2_{P-5}$ at two positions (Ser326Thr and Gln482Lys) were very effective for synthesizing copolymers with a higher 3HV fraction. When recombinant P. putida GPp104 harboring double mutated $phaC2_{P-5}$ gene ($phaC2_{P-5}QKST$) was grown on nonanoic acid, 2.5-fold increase of copolymer content with 3.8-fold increase of 3HV fraction was observed. The $phaC2_{P-5}QKST$-containing Ralstonia eutropha PHB-4 supplemented with valeric acid also produced copolymers consisting of 3HV and 3-hydroxyheptanoate with a high 3HV fraction. These results suggest that recombinants containing $phaC2_{P-5}QKST$ could be useful for production of new PHA copolymers with improved material properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1154-1161
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• 2008

The purpose of this study is to determine the possibility of using Sophorae fructus as natural health food source. To accomplish this purpose, the contents of general and antioxidative nutrients of Sophora fructus were measured. The contents of carbohydrate, crude protein, crude lipid and ash are 75.9%, 16.4%, 2.41%, and 5.2%, respectively, while the calories of Sophora fructus was 337.3 kcal. Total dietary fiber was 15.07% of total carbohydrates. The percentages of water soluble dietary fiber to insoluble dietary fiber were 1.09% and 10.36%, respectively. The protein was composed of a total of 18 different kinds of amino acids. The contents of essential and non-essential amino acids were 2,310.91 mg and 5,218.52 mg. The K was the largest mineral followed by Ca, P and Mg, which means Sophorae fructus is alkali material. The contents of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids were 24.94%, 32.40%, and 32.86%, respectively. Therefore, the amount of the total unsaturated fatty acid was higher than that of any other plant. The content of vitamin C in Sophorae fructus was higher than that of any other plant, which suggests that it could increase blood elasticity. The content of rutin, which is responsible for capillary vessel permeability, was 1.78%. The contents of water soluble antioxidative materials in 1 mL of water-extracted Sophorae fructus were $4.95\;{\mu}g$ which is comparable to 1,560.96 mmol of vitamin C in antioxidant effect. The general nutrients and other antioxidatant bioactive materials in Sophorae fructus were also potential materials for good health food. It is expected that a follow up study on Sophorae fructus through developing processed food and evaluation of their functional properties would provide useful information as a source of medicinal foods.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.92-99
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• 2005

To discriminate the provenance of shelf sediments in the East China Sea, textural and elemental compositions along with strontium isotopic ratio ($^{87}Sr/^{86}Sr$) were analyzed and compared with the sediments originated from Chinese rivers. The sediments in the study area are composed of fine-grained mud with a mean grain size of $47\;{\phi}$ and their $CaCO_3$, contents range from 3.9 to 11.5% (average 7.6%). In the study area, the content of most metallic elements are strongly constrained by sediment grain size (quartz dilution effect) and that of biogenic material and, thereby, their spatial distribution seems not enough for understanding sediment provenance in the study area. The muddy sediments of the Yangtze river have much lower $^{87}Sr/^{86}Sr$ ratio ($0.71197{\sim}0.71720$) than the Yellow Sea shelf muddy sediments which are supposed to be originated from the Huanghe river ($0.72126{\sim}0.72498$), suggesting the distribution pattern of $^{87}Sr/^{86}Sr$ ratios as a new tracer to discriminate the provenance of shelf sediments in the study area. Different source rock compositions and weathering processes between both drainage basins may account for the differences in $^{87}Sr/^{86}Sr$ ratio. Although the ratios show wide range, from 0.71445 to 0.72184 with an average 0.71747 in the study area, they are close to the values of the Yangtze river sediments, suggesting that the sediments were mainly originated from the Yangtze river. The previous studies on the dispersal pattern of modern sediments and the physico-chemical properties of seawater in the Yellow and East China seas support the possibility that the fine-grained Yangtze river sediments can reach to the East China Sea shelf as well as to the southeastern Yellow Sea.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.475-482
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• 2006

The quality characteristics and functional properties of fermented soybean by lactic acid bacteria (FSB) were investigated and compared with those of soybean (control) and commercial cheonggukjang Powder (CGP). The crude protein, lipid, and fiber contents of FSB were similar to those in CGP. The vitamin $B_2$ content in FSB (1.4 mg%) was similar to the control (1.3 mg%) whereas it was remarkably low in the CGP (0.2 mg%). The bright yellow color of FSB determined by Hunter's colormeter was quite different from the dark reddish brown color of the CGP. The pH of FSB was the lowest and thee amino-nitrogen was 517.2 mg%, which was higher than that in CGP (468.1 mg%). Glutamic acid, aspartic acid and leucine were the most abundant amino acids. In particular, the increase in the glutamic acid level was noticeable in FSB. The fatty acid compositions of FSB and CGP were similar to the control. However, the sucrose and fructose levels were lower after fermentation but the glucose level was higher. The results of isoflavone analysis by HPLC showed that the levels of daidzein and genistein in FSB were as much as 48.33 and 52.82 mg%, respectively, which is higher than that found in CGP. The DPPH free radical scavenging effects of FSB and CGP were 1.8 times higher an those of the control. The fibrinolytic activity determined by the diameter of the lysed area on the fibrin plate was the most effective in FSB. In conclusion, it is believed that FSB has a similar or higher quality than CGP. Therefore, FSB is expected to be good functional food material.

• Korean Journal of Food Science and Technology
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• v.45 no.2
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• pp.227-234
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• 2013

The purpose of this study was to determine the possibility of using Oenanthe javanica as a natural health food source. To accomplish this, its general and biological activities were measured. Its carbohydrate, crude protein, crude lipid, and ash contents were 44.7, 9.8, 8.9, and 27.8%, respectively. The K content was largest for minerals followed by Ca, P, and Mg, which means that Oenanthe javanica is an alkali material. The concentrations of total phenol and flavonoids of OJE were $88.9{\pm}0.46$ mg GAE/g, and $28.6{\pm}0.64$ mg QE/g, respectively. Gallic acid, catechin, chlorogenic acid, and caffeic acid in OJE as measured by using HPLC were $0.9{\pm}0.23$, $1.2{\pm}0.19$, $227.1{\pm}0.62$, and $4.0{\pm}0.35$ mg/g. The DPPH and ABTS radical scavenging activities of OJE were 72.2%, and 66.1%, respectively, at $1,000{\mu}g/mL$. The FRAP and reducing power of OJE were 0.79, and 0.41 absorbance units value respectively, at $1,000{\mu}g/mL$. OJE possessed significant antioxidant properties, which suggests its great potential as a functional ingredient for food applications.

• International Journal of Highway Engineering
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• v.6 no.3 s.21
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• pp.1-7
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• 2004

Roads, like bikeways, parkways and walks, are to be just capable of supporting light traffic and traveling public, but they are required to be human friendly and environmental-oriented. Lately soil-solidifier mixture, a kind of soil-cement, has developed and has been applied to the recycling and environment-oriented pavement as the surfacing material. Soil-solidifier pavement structure has been designed by only experience. To design this pavement mechanically, it is necessary to find out basic engineering properties of soil-solidifier mixture. This study focuses on finding out mechanical characteristics of the mixture according to mixture proportions and aging. Test molds with various mixture proportions are made, and then unconfined strength tests are performed for test molds with aging of the mixture. As the result of this study, it is found that the strength of the mixture increases with amount of cement and that maximum strength is achieved at 6%$\sim$8% of the ratio of solidifier and water. The strength increase rapidly until 14 days, after then slowly. After 28 days the strength of the mixture approaches to the constant value. The heat of hydration during curing of the mixture is measured no significantly. It also shows that temperature characteristics of the mixture is similar to that of soil. Since this mixture is mixed with soil and is able to improve engineering problems in pavement due to temperature, this mixture is expected to use effectively in the environment-oriented pavement for light traffic.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.351-363
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• 2020

It is well known that alluvial sediment located in coastal region has been easily affected by geohazard like ground subsidence, marine or meteorological disasters which threaten invaluable lives and properties. The subsidence is a sinking of the ground due to underground material movement that mostly related to soil compaction by water extraction. Thus, continuous monitoring is essential to protect possible damage from the ground subsidence in the coastal region. Radar interferometric application has been widely used to estimate surface displacement from phase information of synthetic aperture radar (SAR). Thanks to advanced SAR technique like the Small BAseline Subset (SBAS), a time-series of surface displacement could be successfully calculated with a large amount of SAR observations (>20). Because the ALOS-2 PALSAR-2 L-band observations maintain higher coherence compared with other shorter wavelength like X- or C-band, it has been regarded as one of the best resources for Earth science. However, the number of ALOS-2 PALSAR-2 observations might be not enough for the SBAS application due to its global monitoring observation scenario. Unfortunately, the number of the ALOS-2 PALSAR-2 Stripmap images in area of our interest, Busan which located in the Southeastern Korea, is only 11 which is insufficient to apply the SBAS time-series analysis. Although it is common that the radar interferometry utilizes multiple SAR images collected from same acquisition mode, it has been reported that the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application could be possible under specific acquisition mode. In case that we can apply the Stripmap-ScanSAR interferometry with the other 18 ScanSAR observations over Busan, an enhanced time-series surface displacement with better temporal resolution could be estimated. In this study, we evaluated feasibility of the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometric application using Gamma software considering differences of chirp bandwidth and pulse repetition frequency (PRF) between two acquisition modes. In addition, we analyzed the interferograms with respect to spectral shift of radar carrier frequency and common band filtering. Even though it shows similar level of coherence regardless of spectral shift in the radar carrier frequency, we found periodic spectral noises in azimuth direction and significant degradation of coherence in azimuth direction after common band filtering. Therefore, the characteristics of spectral bandwidth in the range and azimuth direction should be considered cautiously for the ALOS-2 PALSAR-2 Stripmap-ScanSAR interferometry.

• Journal of the Korean Wood Science and Technology
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• v.17 no.1
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• pp.3-11
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• 1989

This study was carried out to investigate the physical and mechanical properties. durability of adhesive bond and paint film for the basic data which were required to determine the suitability as a raw material for furniture the laminated veneer lumber (LVL) with pitch pine (Pinus rigida Mill). The results obtained were as follows; 1) The proper pressing time for making the LVL was over 45 second per milimeter of LVL thickness. 2) The bending strength of the LVL was lower than that of the solid wood but the compressive strength of the LVL was similar to that of the solid wood. The strength increased with the decrease of veneer thickness. 3) The impact bending absorbed energy of the LVL was 0 to 0.3 kg.m/$cm^2$ in the direction of parallel to the grain. The energy of the LVL was lower than that of the solid wood (0.68 kg.m/$cm^2$). 4) In warm water soaking and cold-dry tests, delamination of adhered layers surface crack, swelling, and color change were not found when the hot pressing time was over 45 second per milimeter of LVL thickness. As a result of soak under vacuum test shrinkage in the direction of parallel to the grain was about -1.0 percent and. was about 3.0 percent in the direction of the perpendicular to the grain. 6) The film cacks on the LVL's surface after the wet and cold-dry test were not found at all. 7) In the use of the LVL for interior decoration it was considered that the surface of the LVL be overlaid crossly with fancy veneers of birch and paulownia, etc. This cross overlayirg methods have resulted in few cracks on the fancy veneer.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.1-11
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• 2008

Statement of problem: Over the past decade, increased demand for esthetically pleasing restorations has led to the development of all-ceramic systems. Recent reports suggest that the all-ceramic crowns have excellent physical properties, wear resistance, and color stability. In addition, numerous ceramics have excellent biocompatibility, a natural appearance, and improved physical bonding with resin composite luting agents. However, the brittle nature of ceramics has been a major factor in their restriction for universal usage. Functional occlusal loading can generate stress in the luting agent, and the stress distribution may be affected by the marginal geometry at the finish line. Tooth preparation for fixed prosthodontics requires a decision regarding the marginal configuration. The design dictates the shape and bulk of the all ceramic crowns and influences the fit at the margin. Purpose: The purpose of this study was to evaluate the stress distribution within marginal configurations of all- ceramic crowns (90-degree shoulder, 110-degree shoulder, 135-degree shoulder). Material and methods: The force is applied from a direction of 45 degrees to the vertical tooth axis. Three-dimensional finite element analysis was selected to determine stress levels and distributions. Results and conclusion: The result of stress level for the shoulder marginal configuration was more effective on stress distribution at 135-degree shoulder margin. But the stresses concentrated around at 135-degree shoulder margin. The stress decreased apically at the surface between cements and alumina core, and increased apically at the surface between alumina core and veneering porcelain.

• Journal of the Korean Applied Science and Technology
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• v.35 no.2
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• pp.423-432
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• 2018

Arthrospira platensis is one of the oldest algae in the world and has been reported to have anti-aging properties, including phycocyanin, tocopherol and beta-carotene. In this study, we tried to search protective activities against UVB-induced reactive oxygen species(ROS) of Arthrospira platensis under indoor cultivation ethanol extracts(ICAE) and outdoor cultivation ethanol extracts(OCAE). The anti-oxidative capacities were evaluated by DPPH radical scavenging activity and SOD-like activities at various concentrations(0.1, 0.5, $1mg/m{\ell}$) of ICAE and OCAE. Zebrafish embryos and HaCaT cells were exposed to UVB radiation and treated with various concentrations(0, 0.01, 0.05, 0.1, 0.5, $1mg/m{\ell}$) of ICAE and OCAE. ROS levels of zebrafish and HaCaT cells were generated by UVB radiation. ROS levels were detected using a fluorescent microscope after DCFH-DA staining. The DPPH radical scavenging activity of ascorbic acid was 73% and SOD-like activity was 86% in the positive control group. ICAE and OCAE at $1mg/m{\ell}$ concentration showed 43, 57% DPPH radical scavenging activity and 20, 19% SOD-like activity. Anti-oxidative of ICAE and OCAE had lower effects than the positive control ascorbic acid but significant results. ROS of UVB-induced zebrafish embryos and HaCaT cells were higher than negative control. ICAE and OCAE treated group decreased ROS concentration dependently than UVB-induced positive control group. These results suggest that Arthrospira platensis ethanol extract may have usability value as a cosmetic material for skin protection.