본 연구에서는 기지금속과의 고상이나 액상의 고용한이 거의 없는 금속-카본(carbon)계에서 고에너지 볼밀공정을 이용하여 고체 윤활 청동베어링용 Cu-C-X계 나노복합금속분말을 제조하고자 하였다. Cu-10wt.%C-5wt.%AI과 Cu-10wt.%C-5wt.%Fe의 혼합분말을 이르곤 분위기의 attritor내에서 기계적 합금화한 후 Cu-C-X의 나노복합금속분말의 미세조직 특성을 조사하였다. AI, Fe를 첨가하였을 때 10시간 이상의 MA공정에서부터 약 10μm이하의 미세한 Cu-C-X나노복합금속분말을 얻을 수 있었으며, MA 시간에 따른 분말의 형상과 미세구조 변화는 금속-금속계의 MA 과정과 유사하게 진행되는 것을 알 수 있었다. Cu-C-X 나노복합금속분말의 X-선 회절시험 결과, MA 시간에 따라 Cu와 C분말의 회절피크의 폭은 넓어지고 회절강도는 감소하였으며, 특히 흑연피크의 MA시간에 따른 소멸은 흑연의 낮은 원자산란계수 때문에 의한 X-선 흡수 영향으로 고찰하였다. Williamson-Hall식으로 계산된 Cu-C-X 나노복합금속분말내의 Cu의 결정립은 15시간 이상의 MA공정에서부터 약 10nm이하의 크기를 가졌으며, TEM 분석결과로는 불규칙한 형상의 약 10-30nm 크기로 복합화된 Cu결정립을 확인할 수 있었다.

The embryogenesis stimulating activity(ESA) had been shown in co-culture of embryos with bovine oviduct epithelial cell(BOEC) and culture in BOEG-conditioned medium. The present study was undertaken to purify and quantify the embryotropic proteins and to determine the optimum concentration of the embryotropic protein for the proper development of embryos. In BOEC-conditioned medium, five major bands of proteins were detected(66, 53, 40, 32 and 24 kDa) by SDS-PAGE. From these proteins, 288pg of protein that had a 32kDa molecular weight was purified by gel filtration column and perfusion chromatography ion-exchange column. When purified protein was supplemented to the in vitro culture media at various concentrations in protein-free media, 2.5g /ml supplement group showed significantly higher rates of embryo development into morula /blastocyst stages than other groups(p<0.05). In conclusion, we purified 32kDa protein from BOEC-conditioned medium and this protein showed optimum embryogenesis stimulating effect at 2.5g /ml.

본논문은 FeCoCiB계 아몰퍼스 자성박막의 주파수에 따른 자기 임피던스(MI)효과에 관하여 조사한 것이다. 영자왜를 갖는 아몰퍼스 자성박막은 고주파 스파터링법에 의하여 제작하였으며, 자계중 열처리를 행하였다. 제작된 자성박막에 직접 외부자계를 인가했을 때, 자성박막의 양단간의 전압진폭은 120[MHz]에서 약 76.2%의 변화를 보였으며, 임피던스는 2.1%/Oe의 변화가 나타났다. 따라서, 제작한 자성박막은 센서소자로서의 가능성을 갖고 있음을 확인하였다.

본 시험은 Holstein종 수소를 조기에 외과적 거세 후 SR-rbST 투여시 사육 단계별 건물 및 영양분 섭취량 변화에 미치는 영향을 구명하기 위하여 Holstein 수소 32두를 공시 하여 얻어진 주요 결과를 요약하면 다음과 같다. 1. 건물 섭취량은 비거세구와 거세구는 큰 차이 가 없었지만 rbSTl구와 rbST2구는 각각 7.88kg과 7.65kg으로 비거세구와 거세구에 비해 6~9% 정도 건물 섭취량이 적었다. 2. NRC 비육우 요구량 대비

This study was designed to observe the effects of hot water soluble polysaccharides extract(PS) from Lentinus edodes on the enzyme activities related with hepatic function and peroxidation in the rats fed butter yellow. The four groups of male SD rats were fed with the diets contained 15% casein(basal diet ; NO group), added butter yellow(BO group) or/and PS(NP, BP group) for 6 weeks. The activities of γ-GTP and GPT in BP were significantly lower compared with BO. The activities of glutathione peroxidase, catalase and lactate dehydrogenase were not significantly different between NP and NO, while those activities were significantly lower value in BP than BO. The activities of glutathione S-transferase of the microsomal and cytosol fractions were significantly low in BP than in BO. The contents of glutathione and malondialdehyde in the liver were considerably low value in BP. In a view of these results the PS of Lentinus edodes prevents the lipid peroxidation and diminishes the liver toxicity caused with butter yellow. The superoxide dismutase activity in cytosolic fraction of liver was not found any effect in all groups. But hepatic function enzyme activities such as catalase and glutathione peroxidase, LDH activities were remarkably decreased in the groups 2(basal diet + PS) and the γ-GTP, GOT and GPT activities, too. In liver, the contents of glutathione decreased by PS supplementation but HDL-cholesterol and total cholesterol ratio in plasma decreased at the groups 3, 4. The γ-GTP, GOT and GPT in plasma were remarkably higher in the rats fed the p-DAB than the control group, too. But above enzyme activities significantly decreased in the groups fed PS.

홍삼의 추출물인 50% ethanol extract, crude saponin, 그리고 lipid soluble fraction이 마우스 대식세포의 oxidative burst를 유발할 수 있는지 여부를 알아보고자 in vitro와 in vivo에 각각의 추출물을 처치하고 hydrogen peroxide 생산을 DCFH-DA를 이용한 형광분광광도법으로 측정하였다. 형광분광법에 의한 hydrogen peroxide의 측정을 최적화하기 위한 DCFH-DA의 농도는 3.2 μM이었고, oxidative burst를 유발하지 못하였지만, zymosan A로 유발한 경우에는 50% ethanol extract에서 가장 높은 hydrogen peroxide를 생산하였다. In vivo 실험에서는, lipid soluble extract에서만 유의하게 증가한(P<0.01) oxidative burst를 유발하였고, ginsenoside(saponin)가 어느 정도 포함되어 있는 50% ethanol extract와 crude saponin은 대조군에 비하여 유의하게 낮은(P<0.05) hydrogen peroxide를 생산하였다. 이는 ginsenoside가 마우스의 nitric oxide 생산을 억제한다는 다른 연구자들의 보고와 일치하는 결과이다. Oxidative burst를 유발한 lipid soluble extract에는 phenol계 화합물, polyacetylene계 화합물, 미량선분 등이 함유되어 있으므로 차후 연구를 통하여 과연 어느 성분이 hydrogen peroxide를 증가시키는지를 규명하는 것이 필요하다.

In order to reduce the small scale fluctuation resulting from shearing holograpy(Park et. al. 1997), differential panel adjustments were performed for 14 m radio telescope of Taeduk Radio Astronomy Observatory with T2 theodolite It appears that this method improves the surface accuracy by about 50μm 50μm . The measured surface accuracy is, at best, 170μm 170μm . The beam efficiency at 86.2 GHz is estimated to be 44% We also found that the elevation at which Park et. al. performed holography was too low.

This research was carried out to investigate the effect of zeranol injection on dry matter(DM) and nutrient intake requirement by growth stage of early castrated bull with 3 treatments(bul1, steer, steer+zeranol) with 28 Holstein bull at National Livestoc

Lactobacillus acidophilus NCFM, Lactobacillus casei YIT 9018, Bifidobacterium longum 8001, and Bifadobacterium longum 8025 at the level of 10^6 cfu/ml were cultured with 10⁴ cfu/ml of Escherichia colt O157:H7 KSC 109 or Salmonella typhimurium ATCC 14028, in order to verify the effects of lactic acid bacteria and bifidobacteria on the growth of the pathogens. In the mixed culture of lactic acid bacteria with E. colt O157:H7 KSC 109, growth inhibition and atypical microcolonies of E. colt O157:H7 KSC 109 were observed. The pathogens inoculated grew for 5 hours (pH 5.3), by the time L. acidophilus NCFM reached the exponential growth phase, and then the surviving pathogens were decreased to 10¹ cfu/ml after 35 hours. When L. casei YIT 9018 was grown with the pathogens, they grew for 10 hours (pH 4.6), by the time L. casei YIT 9018 reached the end of exponential growth phase, and then the surviving pathogens were decreased drastically. Up to the stationary growth phase of lactic acid bacteria, L. acidophilus NCFM exhibited stronger inhibition against the pathogens than L. casei YIT 9018 did, which might be attributed to its faster growth. Likewise bifidobacteria inhibited the growth of the pathogens. tested, bifidobaceria was weaker in the inhibitory activity than lactic acid bacteria. When Bifidobacterium longum 8001 was cultured with the pathogens, E. colt O157:H7 KSC 109 was gradually inhibited at the stationary growth phase of bifidobacteria, atypical microcolonies were formed on Levine EMB medium after 48 hours, and Salmonella grew up to 10^6 cfu/ml, then was drastically inhibited at the exponential growth phage of Bifxdobacterium longum 8001. But when Bifidobacteriuam longum 8025 was cultured with the pathogens, the pathogens grew to the same level of Bifidobacteriuam longum 8025 after 10 hours, then the surviving pathogens were decreased drastically.

Escherichia coli O157:H7 and Salmonella ser. typhimurium are pathogens involved in food poisoning in numerous countries. This study aimed to obtain knowleges on the survival of E. coli O157:H7 KSC 109 and S. ser. typhimurium ATCC 14028 in fermented milk products which were on sale in Suwon Yakult supplier. To the final concentration of 10³-10⁴ cfu/ml of E. coli O157:H7 KSC 109 or S. ser. typhimurium ATCC 14028 in the fermented milks, Metchnikoff, Ace, Yakult, Mastoni and Super100 were inoculated with these pathogens and then were stored at 4 and viable cells of these pathogens were periodically counted. The results showed that the survival of two pathogens differed in the different types of fermented milks tested. Number of surviving E. coli O157:H7 KSC 109 and S. ser. typimurium ATCC 14028 cells (initial inoculum, 10³-10⁴ cfu/ml) were decreased to 10', 102 cfu/ml in Ace after 100 hours, and were decreased gradually to 10¹ cfu/ml in Yakult after 250 hours. In the other fermented milks, viable cells of E. coli O157:H7 KSC 109 was not drastically decreased but those of S. ser. typhimurium ATCC 14028 was decreased gradually to 10² (Mastoni), and to 10¹ cfir/ml (Super100) after 250 hours. It appeared that S. ser. typhimurium ATCC 14028 was more susceptible than E. coli O157: H7 KSC 109 at low pH. Vibale cells of E. coli O157:H7 KSC 109 was not drastically decreased in most of fermented milks tested except Ace and Yakult, but in general, S. ser. typhimurxum ATCC 14028 was drastically decreased in most of the fermented milks. The major inhibition factor against these pathogens in the fermented milks during storage at 4℃ appeared to be the acidity and the metabolites produced by the starters bacteria used in fermented milk products.

풋감을 30일간 저온저장(7℃) 및 냉동저장(-20℃)하면서 성분의 변화를 조사하였다. 수분, 단백질, 지질, 탄수화물 등의 일반성분은 저장방법이나 저장기간에 따른 변화가 없었으며, 조섬유 함량은 냉동저장시는 거의 변화가 없었으나 냉장저장시는 저장기간이 길어짐에 따라 약간씩 감소하였다. 폴리페놀 함량은 냉장, 냉동저장에서 모두 증가하였으나 냉동저장의 경우 증가 폭이 매우 컸다. 총펙틴 함?c은 저장기간이 연장에 따라 감소하였고 수용성 펙틴 함량은 증가하였는데 냉동저장인 경우는 그 증가나 감소 정도가 매우 적었다, 탄닌 함량은 냉동저장시는 거의 변하지 않았으나 냉장저장한 경우는 크게 감소하였다.

This study was carried out to determine the sex of genomic and embryonic DNA using polymerase chain reaction(PCR). Bovine specific(216bp) and Y chromosome speicific DNA primers(l4lbp) were synthesized and tested for sexing. Bovine embryos used in this study were produced by in vitro fertilization. Few blastomeres for PCR were bisected by nicromanipulator and demi -embryos were cultured in TCM 199 medium containing 0.1% of solcoseryl. The results obtained were as follows; 1. Average optical density of genomic DNA extracted from blood of Hanwoo was 1.79 0.14. 2. 2. The ratio of the demi-embryos developed to blastocyst was 62.1 and 81.9% in morula and blastocyst, respectively. 3. When DNA of 2~4, 5~10 and more than 11 blastomeres was amplified with Y chromosome specific DNA primer by PCR, appreance rate of Y specific DNA band was 16.7, 46.2 and 40.0%, respectively. At least 5 to 10 blastomeres were required to determine the sex of embryos. 4. The rate of demi-embryos developed to blastocyst was 73.3% in TCM 199 medium supplemented with 0.1% solcoceryl. but 55.6% in control.

소금농도를 0, 2, 4 및 6%로 조정한 여과제균 배추즙에 김치에서 분리한 7주의 젖산균을 단독 접종하고 30℃에서 배양하면서 증식곡선을 작성하고 이를 이용하여 각 배양조건에서의 유도시간과 세대시간을 구하였다. 소금농도 증가에 따라 증식곡선의 모양이 균주에 따라 서로 다르게 변하였다. 2∼4%의 소금을 첨가하면 모든 젖산균들의 유도시간이 연장되었다. 소금농도를 0%에서 4%로 높였을 때 유도시간은 Leu. paramesenteroides 및 Leu. mesenteroides subsp. dextranicum 가장 연장되었고, 그 다음이 Leu. mesenteroides subsp. mesenteroides, Lac. bavaricus 및 Lac. homohiochii 이었다. 연장기간이 가장 짧은 것은 Lac. plantarum 및 Lac. brevis이었다. 이때 세대시간이 가장 많이 연장된 것은 Lac. bavaricus 및 Lac. homohiochii이었고, 그 다음은 Leu. mesenteroides subsp. mesenteroides, Leu. mesenteroides subsp. dextranicum 및 Leu. paramesenteroides이었다. 연장율이 가장 낮은 것은 Lac. plantarum 및 Lac. brevis이었다. 소금 2% 첨가에 의하여 Leu. mesenteroides subsp. dextranicum 및 Leu. mesenteroides subsp. mesenteroides의 세대시간은 소금 무첨가 보다 약간 길어졌고, Lac. homohiochii 및 Lac. brevis는 변화가 없었다. Lac. plantarum Lac. bavaricus 및 Leu. paramesenteroides는 오히려 약간 단축되었다. 소금농도가 2%에서 4%로 증가하면 젖산균 균종간의 세대시간 서열이 바뀌었다. 소금농도가 낮으면 Leuconostoc속 젖산균들의 증식이 유리하였고, 소금농도가 높으면 Lactobacillus속 젖산균들의 증식이 유리하였다.