Insulin과 tumor necrosis factor alpha(TNF-)에 의한 초기 배아 발생의 조절기작을 알아보고자 생쥐의 상실배를 대상으로 이들이 첨가된 배양액에서 형태발생, 세포증식을 조사하고, 포배에서 mitogen activated protein kinase(MAPK, ERK1/2)의 활성 변화에 미치는 영향을 조사하였다. Insulin은 상실배의 체외발생 및 포배내 할구 수를 대조군에 비해 유의하게 증가시켰으며, TNF-는 발생율을 유의

Hyo Chang Hong. 2001. Referring Expressions of Late Old English: Discourse Functional Analysis of Apollonius of Tyre. Studies in Modern Grammar 25, 55-73. Old English referring expressions have mostly been dealt with in their sentence-internal grammatical functions. In this paper, I claim that, in addition to their case-marking functions, these referring expressions also played an important discourse-functional role in the development of Late Old English narratives. In particular, it is shown that Old English determiners sum and an, in conjunction with zero article, were major factors that determined the relative importance of the entities introduced by them.

A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide(H2S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as H2S oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of H2S inlet concentration and EBCT(Empty Bed Contact Time) on H2S elimination. The pressure drop for particles of size range from 5.6 to 10 ㎜ was 14 ㎜H2O/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under H2S inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of 15.2 ℓ/min. H2S removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of H2S inlet concentration. When EBCT was reduced to 5.5 sec, H2S removal efficiency decreased by about 12 percent. The maximum H2S elimination capacity was determined to be 269g-H2S/㎥·hr.

Water extract of green tea(GTW) and 70% ethanol extract of green tea(GTE) were prepared for the test of antibacterial activity. The sensitivity of Staphylococcus aureus and Salmonella typhimurium to the green tea extracts in various pH of culture broth was tested. Tryptic soy broth(TSB) containing 0∼2%(w/v) of green tea extracts was adjusted to pH 5.0∼7.0 and inoculated with 105/∼106/ cells/ml of each bacteria. The plate counting method and clear zone test were used to determine inhibitory effect of green tea extracts. Green tea extracts completely inhibited the growth of S. aureus at 0.5% level and bactercidal at 0.5∼1.0% level of GTW and GTE at pH 5.0∼7.0. Green tea extracts were bactercidal to S. typhimurium at 1.5∼2.0% level of GTW and 1.0∼2.0% level of GTE at pH 7.0. Sal. typhimurium was more resistant than S. aureus. in same concentration of green tea extracts at same pH. The resistance of S. aureus and Sal. typhimurium was increased with decreasing pH of culture broth. The morphology of S. aureus cells treated with green tea extracts showed damage of cell wall and cytoplasmic membrane. Severely damaged cells of S. aureus lost electron dense material and cytoplasm. Green tea extracts stimulated autolysis and cell death of S. aureus. This result suggests that green tea extracts can be used as an effective natural antibacterial agent in food.

Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

Nitrifier consortium immobilized in polyvinyl alcohol was used for the removal of ammonia nitrogen from synthetic aquaculture water in the airlift bioreactor. At the aeration rate of 0.15 vvm and bead packing volume fraction of 20%, airlift bioreactor was operated effectively for a removal of ammonia nitrogen and for a stability of operation. Ammonia nitrogen removal rate by airlift bioreactor was continuously increased with decreasing hydraulic residence time. At the HRT(hydraulic residence time) of 0.3 hour, ammonia nitrogen removal rate was 84.3 g/㎥·d and the highest ammonia nitrogen removal rate was 130.8 g/㎥·d when HRT was 0.1 hour.

The effects of benzamidoxime concentration, solvents and temperature on the degree of metal extraction were investigated to apply benzamidoxime to heavy metal extraction as chelating agent. Benzamidoxime was synthesized from benzonitrile with hydroxylamine. The chemical structure of benzamidoxime was identified. The degree of heavy metal extraction was increased with increasing the concentration of benzamidoxime and decreasing the extraction temperature. Benzamidoxime was found to be an effective extractant for Cu-extraction by benzene or chloroform. The relationship between the thermodynamic overall equilibrium constant and absolute temperature was expressed as log K = -5.56 + 855T-1. Heat of extraction, △H˚ were calculated from overall equilibrium constants at various temperature and the extraction reaction by benzamidoxime was found to be exthothermic.