• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1199-1206
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• 2006

Plasminogen kringle 5 is a potent inhibitor of endothelial tell proliferation like an endogenous angiogenesis inhibitor, angiostatin consisting of plasminogen kringles 1-4. In this study, we produced the recombinant protein of plasminogen kringle 5 (PK5) employing an Pichia expression system and examined its. effect on~endothelial cell migration and its possible inhibitory mechanism. PK5 was expressed in Pichia pastoris GS115 by fusion of the cDNA spanning from Thr456 to Phe546 to the secretion signal sequence of a-factor prepro-peptide. After methanol induction, the secreted PK5 was purified by using S-spin column. SDS-PACE analysis of the purified protein showed one major band of approximately 10kDa. In in vitro migration assays, the purified protein inhibited dose-dependently the migration of human umbilical endothelial cells (HUVECs) induced by basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF) with an $IC_{50}$ of approximately 500nM. Accordingly, it inhibited bfGF-stimulated extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation in HUVECs at 500nM. In addition, it also potently inhibited bFGF-induced cytoskeletal rearrangement of HUVECs. Thus, these results suggest that Pichia-produced PK5 effectively inhibits endothelial cell migration, in part by suppression of ERK1/2 activation and blocking cytoskeleton rearrangement.

• Journal of Life Science
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• v.27 no.9
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• pp.1078-1085
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• 2017

Free radicals have long been considered damaging to various tissues. An excessive amount of reactive oxygen species (ROS) is known to have detrimental effects on the body and to be linked to numerous pathological conditions, such as cardiovascular disease, cancer, diabetes, and skeletal muscle atrophy. On the other hand, recent findings suggest that ROS is important for maintenance and development of cellular activity. Cells respond to increased oxidative stress by adaptive changes in the expression of a variety of proteins involved in the maintenance of cellular integrity. ROS is also essential for skeletal muscle function and metabolism. It is well known that physical exercise has many health benefits. Paradoxically, physical exercise also stimulates the production of ROS, which result in oxidative stress. Based on evidence amassed in the past decade, exercise itself may be considered an antioxidant because training increases the expression of antioxidant enzymes. In this review, we discuss the processes underlying the generation of ROS and its role in exercise-induced adaptation based on recent evidence. Furthermore, we discuss the possible role of NADPH oxidase in exercise-induced activation of insulin signaling and its effect on longevity.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.177-183
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• 1999

In this paper, we analyze transmission characteristics of ultrashort laser pulses using the property of Raised-cosine pulse which are systematically obtained following Class-2 PRS model. The high-order pulses are easily derived front a modified PRS system model as Class-1 PRS model. This may be based on the fact that the spectra and bandwidths of the high-order pulses are beautifully related to their orders. And we make clear they are very useful to cover wider area and more accurate transmission characteristics of ultrashort pulses than Gaussian or Sech pulse approximations used conventionally. First modifying the generalized PRS system model, we propose a new model for deriving any type of high-order pulse. And we offer a novel analysis method of ultrashort pulse transmission which has any shape and FWHM, using the proposed model. In addition, by fixing the pulse range $\tau$=1(ps) and varying the order of the pulse from n=1 to n=100, we obtain spectra of ultrashort pulses with 1(ps)-100(fs) FWHM's, and width of FWHM in the Class-2 PRS model 50~100(fs) smaller than Class-1 PRS model. As a one-step further, we derive PSD's of their pulse trains when they are applied to Unipolar signaling scheme. These PSD's are derided in the range of possible pulse intervals. All of these results are not only coincided with some conventional experimental works but also will to applied to any pioneering ultrashort pulse in the future.

• Resources Recycling
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• v.25 no.5
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• pp.3-13
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• 2016

Statistics on the urban mining industry is the essential information to develop the urban mining industry systematically and the prerequisite way to understand its related trends. Status on domestic urban mining industry was thus investigated through the integrated method which uses both the top-down way based on the national statistics utilization and the bottom-up way based on field data gathering. Results indicated that the scale of metal resources produced through domestic urban mine was 19.6 trillion won, which corresponds to approximately 22 percent of metal demand in korea. The number of firms for urban mining was 917, and they are mostly placed in metropolitan area and Gyeongsang province. It was also found that about 58 percent of urban mining firms was in small business level less than 10 employees. Compared to the results in 2009, the number of urban mining companies in 2014 generally increased, and that of rare metal companies grew up significantly. This study is particularly different from the conventional statistics investigation on the point of the actual scale findings of metal resources based on the field data.

• Journal of Navigation and Port Research
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• v.34 no.1
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• pp.9-14
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• 2010

Nautical Publications is a special purpose book, or a specially compiled database, that is issued officially by or on the authority of a Government, authorized Hydrographic Office and is designed to meet the requirements of marine navigation such as SOLAS and PSC. Nautical publications include List of Lights, Sailing directions. The SNPWG(Standardization Nautical Publications Working Group) from the IHO is working to implement in computer systems all those elements of interest for Hydrography and Navigation Concerning nautical publications' digitization process, the SNPWG has defined three types of nautical publications: Type 1 : Hard copy(NP1), Type 2 : Digital version, A slight modification of type 1(NP2), Type 3 : Digital version for ECDIS(NP3). Nautical Publications is essential with nautical charts as reference information to navigate. Development of digital nautical publications is needed for liaison with the chart production system, up-to-dateness of hydrographic information, improvement of service. But, Korean status is positioned in NP1. In our study, we surveyed the present status of nautical publications for development strategy of digital nautical publications. We build database of south coast of sailing direction, develop a manager program, convert the contents to KML( Keyhole Markup Language), develop a user program.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.65-68
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• 2009

A Nautical Publication is a special purpose book, or a specially compiled database, that is issued officially by or on the authority of a Government, authorized Hydrographic Office or other elevant ogvernment institution and is designed to meet the requirements of marine navigation Nautical publications include list of lights, Buoys, Beacons, Radio Siganals, Sailing directions. The SNPWG(Standardization Nautical Publications Working Group) from the IHO is working to implement in computer systems all those elements of interest for Hydrography and Navigation Concerning the nautical publications digitization process, the SNPWG has defined three types of nautical publication: Type 1 : Hard copy(NP1), Type 2 : Digital version, A slight modification of type 1(NP2), Type 3 : Digital version for ECDIS(NP3). Nautical Publication is essential with nautical charts as refrerence information to navigation. Development of digital nautical publication is needed for liaison with charts production system, up-to-dateness of hydrographic information, improvement of service. But, korea's status is positioned in NP1. In our study, we surveyed the present status of nautical publciation for strategy of digital nautical publication development. Also, we build database of south coast of sailing direction and develp a program for compilation and management of sailing direction.

• Journal of Information Management
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• v.40 no.3
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• pp.61-77
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• 2009

Recently, enterprises are protecting information assets with the various means of control and management. Nevertheless, they are confronted with the dilemma which the higher securitylevel they request, the lesser efficiency and productivity in short terms they acquire by the inconvenience of business process. In addition, in spite of the steady increase of organization's investment on information protection, the systematic way for the performance measurement of information protection has not been suggested, so that in reality, it is difficult to make the decision to invest on information-protection and elicit the direction to improve it. For this reason, this study intended to establish the concept of the protection and security of information assets of enterprises and to categorize the type of activities to protect information assets into management activity and control activity, and analyze the effects of management activity and control activity for information asset protection on the performance of information asset protection activity and organization. For this research, questionnaire survey was conducted with literature study and the PLS(Partial Least Square) was used to analyze the measurement model and hypotheses testing. The PLS analysis results indicate that management activity for information asset protection affects information asset protection performance. Further, organizational performance is influenced by information asset protection performance. Practical implications of these findings and future research implications are also discussed.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.67-77
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• 2003

The purpose of this study is to provide the criteria for implementing unprotected left turn at intersections with variation of traffic volume on a cross road approach. Using Transyt-7F model, the delays calculated from permissive and protected left turn signal system were compared by gradually increasing the left turn volume for a certain opposing through volume up to the volume limits to which permissive left turn is more effective, Average stopped delay of the intersection was used as the measure of effectiveness in this study. The major conclusions are (1) the lighter the traffic gets in a cross road, the more the allowable left turn volume increases. The allowable left turn volume when the ratio of cross traffic to the concerned approach traffic is 0.6 appears about 50% more than the volume when the ratio is 1.0. (2) Comparing to the criteria of the manual of traffic safety facility, the results when the traffic ratio is 0.6 seem to be most similar the criteria of manual and the results when the traffic ratio are 0.8 and 1.0 appears to be lower than the criteria of manual. (3) The possible amount of making a left turn that is inversely proportional to the opposing through traffic, decreases as the number of opposing through lanes increases. The products of volume need to be used as the criteria of permissive left turn with considerable cautions because of its low consistency.

• Journal of Life Science
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• v.26 no.7
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• pp.758-763
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• 2016

Fatty acid transporters are key mediators of skeletal muscle lipid metabolism. Several protein groups have been implicated in cellular long-chain fatty acid uptake or oxidation, including fatty acid transporter proteins (FATPs), the plasma membrane fatty acid-binding protein (FABPpm), and the fatty acid translocase (FAT/CD36). FAT/CD36 is highly expressed in skeletal muscle and known to be regulated by various factors such as exercise and hormones. Insulin-like growth factor-I (IGF-I) is a well-known regulator of skeletal muscle cells. However, it has not been studied whether there is any interaction between IGF-I and FAT/CD36 in skeletal muscle cells. In this study, the effects of IGF-I treatment on FAT/CD36 induction were examined. Differentiated C2C12 cells were treated with 20 ng/ml of IGF-I at different time points. Treatment of C2C12 cells with IGF-I resulted in increased FAT/CD36 mRNA and protein expression. After 24 and 48 hr of IGF-I treatment, FAT/CD36 mRNA increased 89% and 24% respectively. The increase of both proteins returned to the control level after 72 hr of IGF-I treatment, suggesting that the FAT/CD36 gene is regulated pretranslationally by IGF-I in skeletal muscle cells. These results suggest that IGF-I can regulate the expression of FAT/CD36 in skeletal muscle cells. In conclusion, IGF-I induces a rapid transcriptional modification of the FAT/CD36 gene in C2C12 skeletal muscle cells and has modulating effects on fatty acid uptake proteins as well as oxidative proteins.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.359-365
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• 2021

GEO-KOMPSAT-2A (GK2A) AMI (Advanced Meteorological Imager) Best Detector Select (BDS) map is pre-determined and uploaded before the satellite launch. After the launch, there is some possibility of a detector performance change driven by an abrupt temperature variation and thus the status of BDS map needs to be evaluated and updated if necessary. To investigate performance of entire elements of the detectors, AMI BDS analyses were conducted based on a technical note provided from the AMI vendor (L3HARRIS). The concept of the BDS analysis is to investigate the stability of signals from detectors while they are staring at targets (deep space and internal calibration target). For this purpose, Long Time Series (LTS) and Output Voltage vs. Bias Voltage (V-V) methods are used. The LTS for 30 secs and the V-V for two secs are spanned respectively for looking at the targets to compute noise components of detectors. To get the necessary data sets, these activities were conducted during the In-Orbit Test (IOT) period since a normal operation of AMI is stopped and special mission plans are commanded. With collected data sets during the GK2A IOT, AMI BDS map was intensively examined. It was found that about 1% of entire detector elements, which were evaluated at the ground test, showed characteristic changes and those degraded elements are replaced by alternative best ones. The stripping effects on AMI raw images due to the BDS problem were clearly removed when the new BDS map was applied.