• Animal cells and systems
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• v.16 no.2
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• pp.162-171
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• 2012

We investigated food webs of a $Salix$ $subfragilis$-dominated wetland in the Janghang wetland in the Hangang estuary, which is very close to the Demilitarized Zone, along the west coast of Korea. Our study focused on understanding sesarmine crab ($Sesarma$ $dehaani$)-related food webs in a $S.$ $subfragilis$ forest. For our study, we used carbon and nitrogen stable isotopes and fatty acid biomarkers. We collected samples of plants, animals, and detrital sediment from four quadrats ($5{\times}5m^2$) set in the $S.$ $subfragilis$ community. Samples were collected from September 2006 to June 2009, except during the winter hibernation period of $S.$ $dehaani$. In the wet season, the sediment showed relatively high ${\delta}^{13}C$ and low ${\delta}^{15}N$ signatures compared with relatively low ${\delta}13C$ and high ${\delta}15N$ signatures in the dry season. Mature $S.$ $dehaani$ appeared to feed on fresh leaves and other carbon sources, such as immature individuals or fish, in addition to detrital sediment, which appeared to be the main carbon source for immature crabs. Principal component analysis of fatty acid biomarkers of $S.$ $dehaani$ showed a clear difference between immature individuals (10-30 mm) and mature ones (larger than 30 mm), indicating that the main food source for immature crabs was detrital sediment, whereas mature crabs foraged plants in addition to consuming detrital sediment. On the basis of our results from stable isotope and fatty acid analyses, mature $S.$ $dehaani$ appeared to feed on detrital sediment and fresh leaves of $S.$ $subfragilis$ in summer in addition to engaging in cannibalism of immature individuals.

• Korean Journal of Food Science and Technology
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• v.7 no.2
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• pp.91-95
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• 1975

Neutral lipids of hot pepper seeds were analyzed by employing TLC and GLC methods. This seeds contained TG, SE, FFA, S, DG, and MG, i.e., the main component. TG was found 75. 81%. From the analysis of fatty acids it was found that linolenic (37. 6%). linoleic (27. 0%) and palmitic acid (16. 5%) were presented as the main fatty acids. In the case of SE, linolenic, palmitic and linoleic acids were 38. 1%, 22. 0%, and 20. 9%, respectively, and other acids were presented in small quantities.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1860-1866
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• 2016

Helicopter-related collision accidents with structures mostly occur at landing, especially in a limited visibility environment, which necessitates some secondary equipment like a radar that can generate stationary clutter image. In this paper, we propose an algorithm that makes an image of stationary ground clutter in two dimensional range and azimuth angle domain. We present a mathematical model for the received signals from each clutter patch in the iso range ring and analyze their clutter and Doppler characteristics, assuming that a helicopter-borne radar has a rotational antenna. We propose a filter structure, which suppresses side lobe signal components while extracting a main lobe signal component, and suggest a solution for a problem stemmed from the filtering process. Finally, by conducting a simulation we show the performance of the suggested imaging algorithm on a two dimensional virtual scenario of the topographic clutter.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1868-1870
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• 2000

As a drive for an ETC (Electro-thermal Chemical) launcher, a large pulse power system of a 2.4MJ energy storage was designed, constructed and tested. The overall power system consists of eight capacitive 300kJ energy storage banks. In this paper we describe the design features, setup and operation test result of the 300kJ pulsed power module. Each capacitor bank of the 300kJ module consists of six 22kV 50kJ capacitors. A triggered vacuum switch (TVS-43) was adopted as the main pulse switch. Crowbar diode circuits, variable multi-tap inductors and energy dumping systems are connected to each high power capacitor bank via bus-bars and coaxial cables. A parallel crowbar diode stack is fabricated in coaxial structure with two series 13.5kV, 60kA avalanche diodes. The main design parameters of the 300kJ module are a maximum current of 180kA and a pulse width of 0.5 - 3ms. The electrical performances of each component and current output variations into resistive loads have been investigated.

• Journal of Ginseng Research
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• v.44 no.5
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• pp.673-679
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• 2020

Background: Panax notoginseng saponin (PNS) is the extraction from the roots and rhizomes of Panax notoginseng (Burk.) F. H. Chen. PNS is the main bioactive component of Xuesaitong, Xueshuantong, and other Chinese patent medicines, which are all bestselling prescriptions in China to treat cardiocerebrovascular diseases. Notoginsenoside R₁ and ginsenoside Rg₁, Rd, Re, and Rb₁ are the principal effective constituents of PNS, but a systematic research on the rare saponin compositions has not been conducted. Objective: The objective of this study was to conduct a systematic chemical study on PNS and establish the HPLC fingerprint of PNS to provide scientific evidence in quality control. In addition, the cytotoxicity of the new compounds was tested. Methods: Pure saponins from PNS were isolated by means of many chromatographic methods, and their structures were determined by extensive analyses of NMR and HR-ESI-MS studies. The fingerprint was established by HPLC-UV method. The cytotoxicity of the compounds was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5 -diphenyltetrazolium bromide assay. Results and Conclusion: Three new triterpenoid saponins (1-3) together with 25 known rare saponins (4-28) were isolated from PNS, except for the five main compounds (notoginsenoside R1 and ginsenoside Rg1, Rd, Re, and Rb1). In addition, the HPLC fingerprint of PNS was established, and the peaks of the isolated compounds were marked. The study of chemical constituents and fingerprint was useful for the quality control of PNS. The study on antitumor activities showed that new Compound 2 exhibited significant inhibitory activity against the tested cell lines.

• Journal of Acupuncture Research
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• v.32 no.1
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• pp.97-107
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• 2015

Objectives : The purpose of this study is to explore the antitumor mechanism and effects of tetrodotoxin through a literature review of experimental and clinical studies. Methods : Medical databases, including The Cochrane Library, Pubmed, NDSL, RISS4u and National Assembly Library, were searched for relevant articles published from January 1, 2000 to October 31, 2014 using the keywords 'tetrodotoxin', 'cancer' and 'tumor'. The results were classified into experimental studies(in vitro and in vivo) and clinical studies. Analysis of the results was conducted on several research areas including the mechanism, antitumor effect and adverse effects of tetrodotoxin(TTX). Results : A total of 34 experimental studies(32 in vitro and 2 in vivo) and 3 clinical studies were found in the search. Most of the experimental studies suggested blocking of voltage-gated sodium channels in metastasis of tumor cells as the main antitumor mechanism of TTX. The most common type of cancers mentioned in the experimental studies were prostate and breast cancer. All of the clinical studies were on the application of TTX on moderate to severe cancer-related pain. No adverse effects of TTX were reported in in vivo studies but mild to moderate adverse events were reported in clinical studies. Conclusions : The results show that tetrodotoxin, which is the main component of Tetraodontidae(commonly known as pufferfish) poison, could be clinically used for antitumor therapy. However, further studies should be conducted on its safety.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.1
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• pp.67-73
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• 2008

Interests in natural products have been gradually increasing as well-being era has arrived. Panax ginseng was chosen since it represents Korean traditional medicine as its effect on many age-related symptoms. Panax ginseng absolute essential oil was prepared and analyzed for its main components. Ginseng absolute oil was extracted from Panax ginseng using organic solvent of hexane and ethanol with the yield of 0.146%. The oil was analyzed by GC-MS and main components are sesquiterpenes such as neoclovene, panasinsene, and calarene and more than 110 components were identified from it. The oil was tested for antibacterial activity against general bacteria(E. Coli, S. aureus and P. aeruginosa), yeast, acne germ(Propionibacterium acne) and dandruff germ(Pityrosporum ovale). Panox ginseng absolute essential oil showed the prominent antibacterial activity against Propionibacterium acnes ACCC 6919.

• Korean Journal of Plant Resources
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• v.21 no.5
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• pp.402-407
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• 2008

Total phenol content was obtained from the stem extract of 7.8 (g/100g, D.W.) and root extract of 10.5 (g/100g, D.W.) on Rosa rugosa. S-4 and R-2 compounds were isolated from the stem and root of R. rugosa. The structure of S-4 and R-2 compounds was assigned as catechin by $^{1}H,\;^{13}C$ CNMR signal and TOF-MS. The tannin content of stem extract was 752.5 (mg/100g, D.W.) as 6.3 of gallic acid, 61.5 of epicatechin and 684.8 of catechin. The tannin content of root extract was higher about 2 times (1676.0) as 6.8 of gallic acid, 160.3 of epicatechin and 1508.5 of catechin than that of stem. It was shown that catechin was main compound in the stem and root extracts of R. rugosa. Antioxidant activities were stronger low concentration, and were not different of stem and root extracts. As the results, stem and root of R. rugosa were evaluated, as natural antioxidant resource.

• Convergence Security Journal
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• v.11 no.5
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• pp.109-120
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• 2011

How meteorological situations have affected human life for survival have been an important element of living or military strategy throughout history. In modern society, overcrowding of cities has brought about many problems. Moreover, high-rise buildings and land cover have been causing abnormal weather conditions. The wind corridor, especially in urban areas has been flowing differently from the dominant weather condition of the surroundings. Therefore, the wind corridor in urban areas can be a main component in protecting major national facilities in urban areas from damage. Especially the wind corridor is a main factor to derive harm from poisonous substances in air. This paper seeks to find out the wind corridor in urban areas and the efficiency of that. In addition to that, it studies how to use the direction to protect major national facilities and areas from damage. It is considered that this study will be useful to make defence project, not only for preventing CBR(chemical, biological, and radiological) terrorism and violent assembly, but also for evacuation of people in case of big accidents or natural disasters.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.974-981
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• 2019

Fine dust has become a significant social problem. Diesel engines are used as the main propulsion power source in ships. This study introduces a diesel particulate filter (DPF) that is used as an exhaust after-treatment system for diesel engines to reduce particulate matter known as diesel fine dust. Two materials are used for the DPF: Cordierite and silicon carbide (SiC). In this study, to improve the physical properties of the binder used in the SiC DPF, cordialite was used instead of the SiC-based materials used as the conventional binder to evaluate the thermal durability against high-temperature deformation through the change of the coefficient of thermal expansion. In addition, the physical properties of the silica sol, as a main component of the base coating solution for determining the bond between the binder and the segment, were confirmed. Based on this, the change effect of the binder physical properties was confirmed through experiments by either adding a silane coupling agent or SiC to increase the reactivity of the silica sol.