• Plant Breeding and Biotechnology
• /
• v.6 no.4
• /
• pp.404-412
• /
• 2018

The influenza neuraminidase (NA, E.C. 3.2.1.18), an antiviral, has been the target of high pharmaceutical companies due to its essential role in viral replication cycle. Perilla frutescens (P. frutescens) is used in traditional Chinese medicine for various diseases, such as cold due to wind-cold, headache and cough. In this context, four major polyphenolic compounds including rosmarinic acid-3-O-glucoside (1), rosmarinic acid (2), luteolin (3), and apigenin (4) isolated from P. frutescens were evaluated for their inhibitory effect on recombinant virus H1N1 neuraminidase (rvH1N1 NA). Among the test compounds, rosmarinic acid and luteolin inhibited the rvH1N1 NA with an $IC_{50}$ of 46.7 and $8.4{\mu}M$, respectively. The inhibition kinetics analyzed by the Dixon plots indicated that rosmarinic acid and luteolin were noncompetitive inhibitors and that the inhibition constant, $K_I$, was established as 43.9 and $14.3{\mu}M$, respectively. In addition, 578 genetically diverse accessions and 39 cultivars of P. frutescens were analyzed using HPLC to characterize the diversity of polyphenolic composition and concentration. The individual and total compositions exhibited significant difference (P < 0.05), especially rosmarinic acid which was detected as the predominant metabolite in all accessions (58.8%) and cultivars (62.8%). Yeupsil and Sangback cultivars exhibited the highest rosmarinic acid ($3,393.5{\mu}g/g$) and luteolin ($383.3{\mu}g/g$) content respectively. YCPL177-2 with the high concentration ($889.8{\mu}g/g$) of luteolin may be used as a genetic resource for breeding elite cultivars.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.39 no.2
• /
• pp.327-333
• /
• 2019

For sustainable lunar exploration, the most required resources should be procured on site because it takes tremendous cost to transfer the resources from the Earth to the Moon. The technologies required for use of lunar resources refers to In-Situ Resource Utilization (ISRU). As the ISRU technology cannot be verified in the Earth, a lunar surface environment simulator is necessary to be prepared in advance. The Moon has no atmosphere, and the average temperature of the lunar surface reaches to $107^{\circ}C$ during the daytime and $-153^{\circ}C$ at night. The lunar surface is also covered with very fine soils with sharp particles that are electrostatically charged by solar radiation and solar wind. In this research, generation of vacuum environment with lunar soil mass in a chamber and simulation of electrostatically charged soils are taken into consideration. It was successful to make a vacuum environment of a chamber including lunar soils without soil disturbance by controlling evacuation rate of a vacuum chamber. And an experiment procedure for simulating the charged lunar soil was suggested by theoretical consideration in charging phenomena on lunar dust.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.2
• /
• pp.131-146
• /
• 2014

High-resolution seismic profiles coupled with sediment sampling were analyzed to investigate the acoustic characters and distribution patterns of the late Holocene sediments in Gamak Bay of the South Sea, Korea. The mean grain size of surficial sediment lies around $6.3{\sim}9.7{\Phi}$. Sediments in the bay consist of silt and clay with progressive decrease toward the inner bay. The seismic sedimentary sequence overlying the acoustic basement can be divided into two sedimentary units (GB I and II) by a prominent mid-reflector (Maximum Flooding Surface; MFS). The acoustic basement occurs at the depth between 20 m and 40 m below the sea-level and deepens gradually southward. The GB I, mostly occupying the channel-fill, is characterized by reflection-free seismic facies. It can be formed as late Transgressive System Tract (TST), interpreted tidal environment deposits. MFS appears at the depth of about 15~28 m below the sea-level and is well defined by even and continuous reflectors on the seismic profile. The GB II overlying MFS is composed of acoustically transparent to semitransparent and parallel internal reflectors. GB II is interpreted as the Highstand System Tract (HST) probably deposited during the last 6,000 yrs when the sea level was close to the present level. Especially, it is though that the GB II was subdivided into two layers (GB II-a and II-b) by a HST-reflector and this was classified by wind, sea water flux, and tidal current.