1999년 2월부터 11월까지 강진만의 16개 조사정점에서 동물플랑크톤 군집의 특성을 파악하기 위하여 격월별 조사를 실시하였다. 동물플랑크톤은 9개의 분류군이 출현하였으며 평균 출현량은 2,028indiv. m-3이었다. 월별 출현량은 2월에 최대 5,496 indiv. m-3에서 11월에 최소 78 indiv. m-3 사이에서 변동하였다. 동물플랑크톤 중 요각류는 총 19종이 동정되었는데 월평균 출현량은 42-4,159 in

본 연구에서는 5종의 유산균들 (Lactobacillus reuteri, L. acidophillus, L. bulgaricus, L. casei and Bifidobacterium longum)의 식중독 균들에 대한 항균력을 조사하였다. 각 유산균들을 3가지 서로 다른 조건 (MRS+glucose, MRS+0.5 M glycerol, 0.25 M glycerol solution)에서 배양한 후 그 상층액이 포함된 Moulter Hinton Agar에 8종의 유해균들을 접종하였다. MRS+glucose, MRS+0.5 M glycero에서의 상층액을 이용한 실험에서는 L. reuteri의 항균력이 다른 유산균들에 비해 높지 않았으나 0.25 M glycerol solution에서는 탁월하게 높은 결과를 나타내었다. (p<0.05). 0.25 M glycerol solution에서 나타난 높은 항균력은 L. reuteri가 glycerol을 이용하여 생산하는 reuterin이란 물질 때문이라 생각되며, 0.25 M glycerol solution의 상층액을 500 MHz Nuclear Magnetic Resonance (NMR)를 통해 분석한 결과 reuterin의 존재를 확인할 수 있었다. 3가지 조건 하에서의 항균력 시험 결과 가장 높은 항균력을 나타낸 3가지 유산균들 (Lactobacillus resuteri, L. bulgaricus, L. casei)을 선발, 각각 최고의 항균력을 나타낸 조건으로 배양하여 최소사멸농도 (minimum bactericidal concentration)를 측정한 결과, L. reuteri가 생산한 reuterin이 광범위 항균물질임을 확인하였다. 또한 pH 적정, pepsin 혹은 trypsin 처리를 한 후 3가지 유산균들의 항균력 변화를 조사한 결과 L. bulgaricus와 L. casei의 항균력은 이러한 조건에서 상당히 감소한 반면 reuterin의 항균력은 아무런 영향을 받지않았다 (p<0.05). 이상의 결과들로 보아 주요 유산균들 중에서 L. reuteri의 항균력이 가장 우수하면서 광범위하였으며 이는 L. reuteri가 분비하는 항균물질인 reuterin에 기인한 것으로 사료된다. 또한 reuterin의 항균력은 타 유산균과는 달리 장관내 pH나 단백질 분해효소에 의해 영향을 받지 않으므로 인체나 동물 장관에서 가장 높은 효력을 가진다고 판단할 수 있다.

This study was designed to compare the effectiveness and applicability of the HApS (Hazard Analysis process System; HUKO, Seoul, Korea) based on Petrifilm^(TM)(3M, St. Paul, MN, USA) with the AOAC (the Association of Official Analytical Chemists) standard total aerobic count (TAC) method and coliform count (CC) method for meat products. The comparisons were carried out using 230 meat samples collected from various retailers: 80 pork samples, 80 chicken samples, and 70 beef samples. In the comparison of the correlation coefficient (r) between conventional method and HApS^(TM) method by a linear regression analysis, the correlation coefficients in total microorganism were 0.97767, 0.90712, and 0.95594 in pork, beef, and chicken samples, respectively. The correlation coefficients in coliform count were 0.82062, 0.94833, and 0.96839 in pork, beef and chicken samples, respectively. All the independent t-test on measun:ment values between conventional method and HApS^(TM) method represented no significant differences in the means between two methods at the 0.05 of significance level(α=0.05). Based on the high correlation between HApS^(TM) and the AOAC standard methods in the TAC and CC, it might be compatible to employ the HApS method to measure the microbial contamination in livestock products. HApS^(TM) method was simpler and less time-consuming in sample preparation and procedures faster than the conventional method. These results suggested that the HApS method could be substitute for the conventional methods in the analysis of microbial contamination measurement in meat products.

As a part of basic investigation to Fishery Purge Project for the Special Administrative in Chollanamdo Province, the sedimentary environmental characteristics of Yoja Bay at 15 stations were studied. The analysis was carried out in July, 1998, through st

본 연구에서는 반사필름 멀칭과 북측면의 반사판설치에 의한 보광이 토마토의 광이용에 미치는 영향을 밝히기 위해 토양 및 수경재배를 통해 토마토의 엽온변화, 기공특성, 증산.광합성속도 등의 변화들을 중심으로 검토하였다. 보광 처리에 의해 토마토엽의 기공밀도는 증가하였으나 기공의 크기와 면적은 차이가 얼었다. 근권부의 삼투포텐셜이 낮으면 광반사에 의한 기공저항이 컸고 증산속도는 낮았으며 엽온은 40.62℃까지 상승했다. 또한 보광에 의해 광합성속도도 저하했으나 엽록소 함량에는 차이가 없었다. 반사필름 멀칭으로 온실가루이의 기피효과는 있었다 약광기 동절기에 반사필름 멀칭 등의 보광처리에 의한 증수나 품질향상은 엽의 기공밀도의 증가로 활발한 증산 .광합성작용으로 체내의 물질대사나 생장에 영향을 주고 그 결과 간접적으로 무기성분의 흡수나 분배에 영향을 주어 생육 및 수량 둥이 양호했다고 생각된다.

6-[(N-3,4-Dibromophenyl)amino]-7-chloro-5,8-quinolinedione(RCK13) was tested for antifungal activities. The MIC values were determined by the two-fold dilution method. The therapeutic potential of RCK13 had been assessed in comparison with ketoconazole and fluconazole against systemic infections with Candida albicans in normal mice. RCK13 had ED_(50), 0.80±0.21 mg/kg but ketoconazole had ED_(50), 8.00±0.73 mg/kg respectively. And administered RCK13 at the ED_(50) for 14 days improved survival rates as well as ketoconazole. Acute oral toaicity studies of RCK13 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK13 were low and LD_(50) values were over 2,850 mg/kg in ICR mice. The genotoxicities of RCK 13 had been evaluated. RCK13 was negative in Ames test with Salmonella ryphimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK13 with in vivo mouse micronucleus assay. RCK13 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK13 has no genotoxic potential under these experimental conditions.

CdS/CuInSe2태양전지의 광흡수층인 CuInSe2박막을 In2Se3와 Cu2Se 이원화합물을 precursor로 하여 진공증발법으로 제조하였고 특성을 분석하였다. 먼저 유리기판위에 0.5μm 두께의 In2Se3를 susceptor온도를 변화시켜가면서 증착한 결과 400˚C에서 가장 평탄하고 치밀한 박막이 형성되었다. 그 위에 Cu2Se3를 진공증발시켜 증착함으로써 in-situ로 CuInSe2박막을 형성시키고 In2Se3를 추가로 증발시켜 CuInSe2박막내에 존재하는 제 2상인 Cu2Se를 제거시켰다. 이 경우 susceptor온도가 700˚C 일때 미세구조가 가장 좋은 CuInSe2박막이 형성되었으며 약 1.2μm 두께에서 약 2μm의 결정립크기와 (112) 우선배향성을 가졌다. 추가 In2Se3양이 증가함에 따라 CuInSe2박막의 조성편차보상으로 hole 농도가 감소하고 전기 비저항이 증가하였고, optical bandgap은 거의 일정한 값인 1.04eV의 값을 가졌다. Mo/유리기판 위에 증착한 CuInSe2박막도 유리기판 위에 증착한 박막과 비슷한 미세구조를 가졌으며, 이 박막을 토대로 ZnO/CdS/CuInSe2/Mo 구조를 갖는 태양전지 구현이 가능할 것으로 생각된다.

기계적 합금화 방법으로 제조된 A-8wt%Fe합금분말의 진공고온 소결거동을 분석하였고 이 소결체의 고온변형거동을 연구하기 위하여 350˚C-450˚C의 온도 범위에서 여러 변형률속도로 압축 시험을 수행하였다. 또한 이 소결체의 열적안정성을 조사하기 위하여 300˚C-500˚C온도 범위에서 각각 60시간 동안 열처리한 후 경도시험을 수행하였다. 압축응력은 변형률이 증가함에 따라 급격히 증가하여 변형률 약 3%에서 최대응력에 이르렀으며, 최대응력 이후 다소 연화현상을 보인 후 유동응력은 가공경화돠 동적 재결정의 평형률 30%까지 일정하였다. 또한 60시간 열처리에 따른 소결시편의 경도는 400˚C에서 부터 급격히 감소하였다.

If the MR fluid damper does not work, the magnetic powder (carbonyl iron powder) will sediment. To overcome this problem, we developed an EMR (Enhanced Magneto Rheological Fluid) fluid and evaluated control performance. For the dynamic load test using MR fluid and EMR fluid was conducted to evaluate control power and DR (Dynamic Range). In the damper performance test, the current was tested at intervals of 0.5A from 0.0A to 2.5A, and the control power of the EMR fluid was 84% compared to the control power of the MR fluid, The DR of the EMR Damper was 7.5. When the DR is 5.0 or higher, it is generally used as a semi-active control device. Therefore, the EMR fluid has proved its usability as a semi-active control device by showing 7.5 DR to 76% control performance of existing MR damper.

Background : Miscanthus sinensis is a C4 crop with high photosynthetic efficiency and is known as a representative cellulose-based bio-energy crop originating in East Asia such as Korea, Japan, and China. It also has a high resistance to environmental conditions such as low temperature and drying and pests. However, many studies on the antioxidant activity of the M. sinensis have not been conducted. Therefore, this study was conducted to measure total phenol and total flavonoid contents of the M. sinensis accessions collected from some countries and to select the M. sinensis accessions with rich total phenol and total flavonoid contents. The results of this study can be used as basic data for future breeding. Methods and Results : This study carried out the total phenol and total flavonoid contents analysis of M. sinensis collected from different country to preserve genetic resources. Total 205 accessions of M. sinensis were collected from the USA, China, Korea, Japan, Thailand and Zambia. Their leaves were extracted with 100% methanol and concentrated at 45℃. To determine total phenol and total flavonoid contents, we measured the total phenolic content and total flavonoid content. The highest total phenolic conten t(81.04 ± 0.02 ㎎·GAE/g) showed in the accession (PMS-178) from China. The highest total flavonoid content (32.66 ± 0.01 ㎎·QE/g) showed in the accession (KMS104) from Korea. On the other hand the lowest total phenolic content (1.11 ± 0.00 ㎎·GAE/g) and the total flavonoid content (0.81 ± 0.00 ㎎·QE/g) were obtained from the accession (M. sinensis ‘Super Stripe’) from USA. Conclusion : In this study, we analysed the total phenolic and total flavonoid contents by country of origin.

Background : Miscanthus is a species of flowering plant in the family poaceae, native to Eastern Asia throughout most of China, Japan, Taiwan and Korea. It is diploid hybrid grass used as bioenergy plant, biomass production and high quality of cellulose and ethanol production. It is an herbaceous perennial grass, growing up to 0.8 - 3.0 m tall, rarely 4.0 m, forming dense clumps from an underground rhizome. Recently, Studies on Miscanthus have been carried out on the growth characteristics and to see the antioxidant difference of Miscanthus for functional materials in various regions. Methods and Results : This study carried out the antioxidant activities of Miscanthus collected from different countries of origin. Two hundred one accessions of Miscanthus were collected in 7 countries (China, Japan, Korea, Taiwan, Thailand, U.S.A, Zambia). Initially, each leaves were extracted with 70% ethanol to determine actioxidant activty. Antioxidant activities were evaluated by DPPH and ABTS radical scavenging activity. The highest DPPH radical scavenging activity showed in the accession [M. sinensis ‘Kleine Silberspinne (little silver spider)’] from U.S.A (RC50: 10.66 ± 15.46 ㎍/㎖) and the lowest showed in the accession (M. sinensis ‘Supr Stripe’) from U.S.A (RC50: 188.03 ± 0.86 ㎍/㎖). The ABTS radical scavenging activity showed the highest in the accession (No.401: JM0310.002) from Japan (RC50: 17.97 ± 3.26 ㎍/㎖) and the lowest showed in the accession (M. sinensis ‘Supr Stripe’) from U.S.A (RC50: 416.88 ± 10.05 ㎍/㎖). Conclusion : The antioxidant activity of Miscanthus showed in average DPPH radical scavenging activity (RC50: 74.05 ± 3.74 ㎍/㎖) and ABTS radical scavenging activity (RC50: 81.46 ± 3.95 ㎍/㎖). In this study, it may be used for feed crops or food crops as a functional material.

Background : Glycyrrhiza uralensis Fischer is one of most important medicinal (Glycyrrhizae radix) herbs in traditional oriental medication and they are also important commercial products used worldwide in sweetening and flavoring. They contain the similar compounds, such as the triterpenoid saponins and flavonoids. Therefore, it is necessary to develop more efficient and sustainable methods for the production of G. uralensis Fischer and its medicinal constituents. This study was accomplished to investigate the effect of medium composition on in vitro propagation and plantlet regeneration from nodal explants of G. uralensis Fischer, and to establish a reliable protocol for micropropagation. Methods and Results : Young and actively growing stem segments were excised from adult plants of new cultivar ‘manju’. They were cut into a 1cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for two weeks. For shoot multiplication, one-node stem segments, approximately 1 ㎝ in length, were taken from in vitro derived shoots and subcultured. After four weeks of culture, the efficacy of each medium on shoot proliferation and growth was determined, and these shoots were transferred onto medium with different auxin hormones for rooting. Conclusion : After seven to ten days of culture, shoots began to emerge from axillary buds. They showed a vigorous growth and elongation in multiplication medium. During culture period, in vitro cultured plantlets showed significantly different responses to the respective medium with different plant growth regulators. Our experiments confirmed that in vitro growth and multiplication of palntlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

Background : Panax ginseng C. A. Meyer is a medicinal plant corresponding to 'raw materials for food use' in Korean food standards codex, and it is known that it has the same origin although it is classified into wild ginseng, cultured ginseng and red ginseng. It varies morphologically, molecularly, depending on the cultivation or habitat environment. In this study, we carried out experiments for the morphological differentiation of cultured ginseng (Hongcheon, Gunsan, Miryang) and adventitious roots culture of wild mountain ginseng (by company). Methods and Results : Morphological observations were made with resin sectioning method (RSM). The test method was sampled, preprocessed, embedded, segmented, slid and then observed with an optical microscope. The epidermis, cortex and vascular tissues were identified in the inner cross section of adventitious roots culture of wild mountain ginseng. Phloem was formed at the center, and xylem was formed at the side. In cultured ginseng, the organs of the vascular tissues were differentiated into two, whereas in the adventitious roots culture of wild mountain ginseng, one vascular tissue was formed due to the thin adventitious. Conclusion : Plant resources have the diversity of using the same or different origins depending on their distribution. The morphological differentiation method of ginseng and adventitious roots culture of wild mountain ginseng is expected to be based on domestic fair trade to prevent discrimination.