• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.30-37
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• 2006

We performed experiments on the uptake and excretion of dissolved organic phosphorus (DOP) using two toxic dinoflagellates, Alexandrium tamarense Lebour (Balech) and Gymnodinium catenatum Graham, isolated from Hiroshima Bay, Japan. ATP (adenosine triphosphate), UMP (uridine-5-monophosphate), G-6-P (glucose-6-phosphate) and Glycero-P (glycerophosphate) were used as DOP sources in preliminary uptake experiments. ATP was selected as the DOP species for the short-tenn uptake experiment because preliminary experiments showed it to be the DOP source used by both species. Although the $K_s$ values of A. tamarense and G. catenatum (5.63 and $7.61{\mu}M$, respectively) obtained from the short-term experiments for ATP were only slightly higher than those reported for dissolved inorganic phosphorus (DIP), the ${\rho}_{max}$ values (5.04 pmol/cell/h and 13.4 pmol/cell/h, respectively) were much higher. The DOP excretion rate in batch-culture experiments was estimated at 0.084 pmol/cell/h for A. tamarense and 0.012 pmol/cell/h for G. catenatum, accounting for about 30% and 25%, respectively, of the assimilated phosphorus. Our results suggest that the DIP-depleted conditions of Hiroshima Bay favor these two species by supporting their ability to use DOP.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.190-194
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• 2005

In our search for monoamine oxidase (MAO) inhibitors from natural resources, we found that the methanol extract of the roots of Sophora flavescens showed an inhibitory effect on mouse brain monoamine oxidase (MAO). Bioactivity-guided isolation of the extract yielded two known flavonoids, formononetin (1) and kushenol F (2), as active compounds along with three inactive compounds, oxymatrine (3), trifolirhizin (4), and ${\beta}$-sitosterol (5). Formononetin (1) and kushenol F (2) showed significant inhibitory effects on MAO in a dose-dependent manner with $IC_{50}$ values of 13.2 and $69.9\;{\mu}M$, respectively. Formononetin (1) showed a slightly more potent inhibitory effect against MAO-B ($IC_{50}:\;11.0\;{\mu}M$) than MAO-A ($IC_{50}:\;21.2\;{\mu}M$). Kushenol F (2) also preferentially inhibited the MAO-B activity than MAO-A activity with the $IC_{50}$ values of 63.1 and $103.7\;{\mu}M$, respectively.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.139-142
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• 2009

The effect of calcium cyanamide (China-made) soil fumigation on the growth of the ginseng pathogen Rhizoctonia, Pythium), soil microbes, and seed germination of lettuce and radish was investigated. At twice the recommended level (2S0-ppm $CaCN_2$), the growth of Rhizoctonia and Pythium, and the seed germination, were not inhibited. Rather, the effective level was 10,000 ppm. The powder form was more effective than the granular form in inhibiting pathogen growth and seed germination. The lettuce seed was also more sensitive than the radish seed. Calcium cyanamide appearedto decrease the fungi population and to increase Actinomycetes in the soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.126-130
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• 2004

This study is to identify the physiological traits of submergence-tolerant varieties of rice plants (Oryza sativa L.) in Yeongnam area, southeastern part of Korea, where the reduction of rice yield due to submergence is remarkably severe. In the present study, two tolerant varieties of rice plants were selected from over 30 rice varieties grown in under a 10-day period. The tolerant varieties selected from a submerged paddy field. As a control, one intolerant variety of rice plant was chosen. Of the tolerant variety Samgangbyeo, rather than Haepyungbyeo, had a lower dissolved oxygen consumption and maintained a higher dry weight than the intolerant variety. The leaf photosynthetic rates (LPS) of the two tolerant varieties were significantly higher than that of the intolerant-variety after four days of submergence treatment. These results indicate that lower dissolved oxygen consumption in a limited pool is prevented by ethylene formation in the tolerant varieties, which may be a mechanism of submergence tolerance.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.4
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• pp.107-119
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• 2013

바이오매스 가스화는 세계적인 증가 추세에 있는 에너지 수요를 충족할 수 있는 기술 중의 하나이다. 바이오매스 가스화를 통해서 농업 폐기물 등 다양한 바이오매스 자원을 에너지로 전환할 수 있고 $CO_2$ 배출량 또한 줄일 수 있다. 본 연구에서는 COMSOL$^{(R)}$ 3.4 소프트웨어를 이용하여 바이오매스 원료와 운전 조건에 따른 가스화 효율 및 합성가스 조성의 변화를 분석하였다. 원료와 구동조건을 최적화하기 위해 가스화 모델을 세우고 원료와 구동조건을 달리하여 합성가스의 성분을 분석 및 예측하였다. 이 모델은 물리적인 실험을 통해 알고 있는 조건을 통해서 합성가스 성분을 시간에 따라 예측할 수 있다. 모델을 이용하여 함수비 5~30 %, 공기중 산소함량 5~50 %, 공기공급 유량 5~45 L/min, 온도 973~1273 K의 조건에서 합성가스의 성분을 예측한 결과 실제 실험 결과와 일치하는 것을 알 수 있다. 모델링 결과 양질의 합성가스를 생산하려면 원료의 회분함량이 적어야 하고 수소 함량이 높은 합성가스를 생산하려면 반응 온도가 높게 유지되고 원료의 함수비가 높아야 한다. 가스화장치의 온도를 높이면 합성가스의 성분 중 CO의 함량이 많아지고, CO의 함량이 많아지면 가스의 발열량이 높아지는 것을 알 수 있다. 또한 CO의 농도가 높고 발열량이 높은 합성가스를 생산하기 위해서는 ER값은 작아야 한다.

• Mycobiology
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• v.45 no.4
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• pp.344-352
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• 2017

During a survey of fungal diversity of the order Mucorales, three zygomycete isolates, CNUFC-YR113-1, CNUFC-KNU16-7, and CNUFC-BS1-1 were isolated from freshwater and soil samples in Korea. The strains were analyzed both morphologically and phylogenetically based on internal transcribed spacer and 28S rDNA gene sequences. Based on their morphology and phylogeny, the CNUFC-YR113-1 and CNUFC-KNU16-7 isolates were identified as Actinomucor elegans, and CNUFC-BS1-1 was identified as Mucor minutus. To the best of our knowledge, the species A. elegans and M. minutus, belonging to an undiscovered taxon, have not been previously described in Korea.

• The Plant Pathology Journal
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• v.27 no.1
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• pp.1-7
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• 2011

Colletotrichum panacicola isolates were obtained from anthracnose lesions of Korean ginseng and compared with four Colletotrichum species in morphology, molecular phylogeny and pathogenicity. Based on morphological characteristics, C. panacicola was easily distinguished from Colletotrichum gloeosporioides but not from Colletotrichum higginsianum, Colletotrichum destructivum and Colletotrichum coccodes. A phylogenetic tree generated from ribosomal DNA-internal transcribed spacer sequences revealed that C. panacicola is remarkably distinguished from C. gloeosporioides and C. coccodes but not from C. higginsianum and C. destructivum. However, molecular sequence analysis of three combined genes (actin + elongation factor-$1{\alpha}$ + glutamine synthatase) provided sufficient variability to distinguish C. panacicola from other Colletotrichum species. Pathogencity tests showed that C. panacicola is pathogenic to Korean ginseng but not to other plants. These results suggest that C. panacicola is an independent taxon distin-zguishable from C. gloeosporioides and other morphologically similar Colletotrichum species.

• Research in Plant Disease
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• v.12 no.2
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• pp.103-107
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• 2006

An array of surveys was designed to improve current Pesticide Management Law and Acts by investigating farmers' usage of pesticides and by assessing applicability of Plant Protection Certificate to register local pesticide markets or related businesses. This study indicates that most farmers choose pesticide recommended by local pesticide market dealers. This survey also indicates serious misuse or overuse of pesticides by farmers probably due to inappropriate recommendations. To guarantee rational use of pesticides by the end users, most experts in the plant protection areas have realized the importance of the Certificate as a license to register the local pesticide markets. To the end, current Pesticide Management Laws and Acts need to be revised to ask pesticide-dealing workers to take the Plant Protection Certificate.

• Korean Journal of Pharmacognosy
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• v.35 no.1 s.136
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• pp.52-61
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• 2004

Inhibitory activities of 264 methanol extracts, which were prepared from different parts of 210 kinds of wild and medicinal plants, against human thrombin were evaluated. Based on the anti-coagulation activity determined by thrombin time and activated partial thromboplastin time, the 14 extracts were screened. The fibrinolytic activity, heat stability and inhibition of other proteolytic digestive enzymes, such as pepsin, papain, trypsin and chymotrypsin, of the 14 extracts were further determined, and Ginko biloba (herba), Ephedra sinica (radix), Reynoutria elliptica (herba), Amomum tsao-ko Crevost (fructus), and Magnolia officinalis Rehd. et Wils (bark) were finally selected as possible plant sources for anti-thrombosis agent. These results suggested that medicinal and wild plants could be the potential source of thrombin inhibitor.

• Ocean Science Journal
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• v.40 no.4
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• pp.183-190
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• 2005

We investigated the seasonal variability of tree alkaline phosphatase activity in seawater and alkaline phosphatase hydrolysable phosphorus (APHP) at 3 stations in Hiroshima Bay using alkaline phosphatase extracted from the dinoflagellates Alexandrium tamarense and Gymnodinium catenatum. The dissolved inorganic phosphorus (DIP) was lower than $1\;{\mu}M$ all samples; the lowest values were in May. The amount of APHP was high at the surface and bottom waters of all stations in May, showing DIP-depleted conditions. In August and November, the amount of APHP was much less than the amount of APHP in May, indicating that the availability of dissolved organic phosphorus (DOP) for these species was low and/or uptake during the dinoflagellate blooming might have occurred in the area. The results obtained from short-term variations of AP activity might suggest that the growth of dinoflagellates in this season may be partly supported by the AP produced by other diatoms.