• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.655-662
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• 2013

The antioxidant and anticancer effects of the edible mushrooms Lentinus edodes (LE, Pyogo mushroom) and Agaricus blazei (AB, Agaricus mushroom), and the medicinal mushrooms Cordyceps militaris (CM, Dong chunghacho), Ganoderma lucidum (GL, Youngji mushroom), Inonotus obliquus (IO, Chaga mushroom), and Phellinus linteus (PL, Sangwhang mushroom) were studied in vitro. The bioactive components were extracted by methanol. The antioxidant effects were evaluated using the DPPH and hydroxyl radical scavenging assays. The antioxidant activities of medicinal mushrooms (35~90%) were higher than edible mushrooms (4~23%). The in vitro anticancer effects of the mushrooms were evaluated using the MTT assay in AGS gastric adenocarcinoma cells, HCT-116 colon carcinoma cells, and HepG2 hepatoma cells. The medicinal mushrooms CM, GL, IO, and PL showed 28~91% inhibition, while the edible mushrooms LE and AB exhibited 5~40% inhibition. The medicinal mushrooms, compared to edible mushrooms, effectively down-regulated the gene expression of the anti-apoptosis related gene Bcl-2 and inflammation-related genes iNOS and COX-2, and up-regulated the pro-apoptosis gene Bax (p<0.05). Total polyphenol and flavonoids contents of the medicinal mushrooms were 9.1~35.7 mg/g, while the edible mushrooms showed 0~13.3 mg/g. This study showed that antioxidant activities and anticancer activities in vitro increased in the order LE, AB, GL, CM, IO and PL. LE and AB showed the lowest effects among the samples, GL and CM had medium effects, and IO and PL exhibited the highest effects in the antioxidant and anticancer effect for three different human cancer cells. Taken together, PL resulted in the highest and LE the lowest effects in this study.

• Journal of the Korean earth science society
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• v.23 no.3
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• pp.280-293
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• 2002

In this study, we analyzed the long-term distribution patterns of $CH_4$ determined from the Moo-Ahn (MAN) observatory in relation with those derived from the world major background monitoring sites. Comparison of the data were made using those data sets collected for the period between Aug. 1995 to Dec. 1991. The mean $CH_4$ concentration of MAN observatory was measured to be 1898${\pm}$85.3 ppb, recording the highest concentration of all the monitoring sites. When the concentration of $CH_4$ for different stations was compared over latitudinal scale, its concentration appeared to increase systematically as a function of latitude with an exception of MAN (and the other Korean monitoring site at Tae Ahn). Moreover, such phenomenon was more distinctive in Northern than Southern Hemisphere. According to the analysis of the monthly distribution patterns of $CH_4$ at MAN observatory, its concentration level began to increase from the months of February/March and peaked during August. In addition, when the level of oscillation in monthly concentrations (between the maximum and minimum values) was checked, differences were significant between MAN and other monitoring stations. If the rate of concentration change was checked using the data sets collected for this limited time period in terms of linear regression analysis, results for MAN showed the highest annual increasing rate of 16.5 ppb. It is hence suggested that the largest variability in the $CH_4$ distribution patterns at MAN observatory may be reflected by the high irregularity in its source/sink processes.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.