• 한국가금학회지
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• 제28권3호
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• pp.231-237
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• 2001

육계를 13주간 사육하면서 5주령부터 시험사료를 급여한 후 세포표면항원의 발현에 미치는 영향을 측정하기 위하여, 아마종실과 항산화제를 첨가하지 않은 대조구($T_{1}$ ), 아마종실만을 첨가한 사료($T_{2}$ ), 아마종실과 u-toco-pherol을 첨가한 사료($T_{3}$ ), 아마종실에 u-tocopherol과 셀레늄을 첨가한 사료($T_{4}$ )를 육계에 급여한 바 면역반응에 미치는 영향은 다음과 같았다. 1차 면역에 관여하는 monocyte 군은 시험사료의 급여기간이 증가할수록 $T_{1}$ 에 비하여 $T_{2}$ , $T_{3}$ , $T_{4}$ 구에서 유의적으로 증가하는 경향을 보였는데 그중 $T_{2}$ 구와 $T_{3}$ 구에서 많이 증가되었다. B세포는 시험사료의 급여기간보다는 급여사료에 따라 증가하였는데,$T_{2} , $T_{3}, $T_{4}$ 구는 $T_{1}$ 구에 비하여 2배 이상 증가하였다. CD4 양성반응(T helper cell)과 CD8 양성 세포(T $cytotoxic^pressor cell)는 $T_{2}$ , $T_{3}$ ,$T_{4}$ 구는 $T_{1}$ 구보다 증가하였으나 사료에 따라 일정한 차이는 없었다. MHC classII는 시험사료의 종류나 급여 기간에 따라 차이는 없었다.었다.

• 통상정보연구
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• 제2권2호
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• pp.97-110
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• 2000

1990년대 중반 인터넷이 상업용으로 발달하면서 전자상거래의 경제적 효과에 관한 연구가 활발히 진행되고 있다. 인터넷은 자유로운 시장진입을 가능하게 하고 제품 및 가격에 대한 완전한 정보를 공유하게 함으로써 경제적 비효율성을 제거할 수 있다. 그러나 한편으로 인터넷상의 검색비용 등이 실세계에서의 비용과 비교할 경우 그 차이가 매우 작을 수 있다는 주장도 있다. 인터넷으로 판매하는 상품들의 가격이 전통상점에서의 판매가격보다 낮은 지의 여부는 결국 실증문제로 귀착된다. 본 연구는 한국에서 서적과 음반CD에 대해 인터넷상점과 전통상점에 의해 부과되고 있는 실제가격들을 비교함으로써 이러한 질문에 대한 해결을 시도하고자 한다. 이들 두 제품은 한국은 물론 해외에서도 전자상거래로 가장 빈번히 거래되고 있는데다 제품의 표준화가 여타제품에 비해 비교적 잘되어 있는 제품들이다. 본 연구는 실증분석을 위해 2000년 9월 18~30일 동안 조사원들에 의해 실제 매장과 인터넷사이트에서 수집된 가격관찰치를 집계하고 이들 자료에 대한 통계적 검정을 시도하였다.

• Bulletin of the Korean Chemical Society
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• 제21권8호
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• pp.805-808
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• 2000

Mixed crystal powders based on Cd,Fe, and S have been synthesized by varying the ratio of CdS and $FeS_2in$ order to find a suitable material usefuI for the effectivc conversion of solar energy. Hydrogen gas was evolved only with CdS/Ptby photocatal ytic reaction under white light in an aqueous 1 M sodiumsulfite solution. From electrochemical studies of semiconductor electrodes. itwas shown that the onset potential shifted to the positive direction and that the bandgap energy also decreased as the molar ratio of Fe increased. A hydrogen evolution mechanism in terms of the conduction band potential and hydrogen evolution potential is proposed.

• 대한한방내과학회지
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• 제24권1호
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• pp.33-43
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• 2003

Objective : This study was carried out for the purpose of proving the effect of anti-allergic efficacy on B cells and the mast cells of the BALB/C mouse by the abstraction from a Moutan cortex. Methods & Results : In order to know what the effect of an abstraction from Moutan cortex and about the expression of CD23 and IgE, IC-2 cell (mouse mast precursor cells that was dependent on IL-3), it was necessary to be activated. We then analyzed it from the flow of cytometry on the increase and the divorce of the B cells activated by anti-CD40. In order to know what the effect of it was on the organization of cytokine gene expression from the increase and divorce of the B cells and allergic acting by Moutan cortex, we found it necessary to examine the IC-2 cells and B cells. At the same time, as we examined the histamine release of IC-2 cells by ELISA method, we also examined the effect of Moutan cortex on the increase and divorce of the B cells by 3H-thymidine uptake method. We then analyzed the release of IL-4, IgE and histamine. Conclusions : As a results, Moutan Cortex promoted blood supply by extending the blood vessel of nasal mucous, which was contracted by the hypertrophied nasal mucous.

• 한국환경농학회지
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• 제25권1호
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• pp.40-46
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• 2006

This study was initiated to evaluate the inhibitory effect of selected heavy metals on the growth of Acinetobacter sp. Down as one of the phosphorus accumulating microorganisms (PAO) involved in the enhanced biological phosphorus removal (EBPR) process of the wastewater treatment plant. Acinetobacter sp. was initially selected as a starting model microorganism and was grown under aerobic condition for this experiment. The heavy metals selected and investigated in this study were cadmium (Cd), copper (Cu), mercury (Hg), nickel (Ni), and zinc (Zn). Median $(IC_{50})$ and threshold $(IC_{10})$ inhibitory concentrations for Cd, Cu, Hg, Ni, and Zn were 2.95 and 1.45, 4.92 and 2.53, 0.03 and 0.02, 1.12 and 0.43, 14.84 and 5.46 mg $L^{-1}$, respectively. We demonstrated that most of heavy metals tested in the experiment inhibited the growth of Acinetobacter sp. in the range of predetermined concentrations. Based on the data obtained from the experiment, Hg was the most sensitive to Acinetobacter sp., then Ni, Cd, Cu, and Zn in order.

• 한국환경농학회지
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• 제29권2호
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• pp.189-196
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• 2010

The removal of phosphorus (P) in the wastewater is essential for the prevention of eutrophication in the river and stream. This study was initiated to evaluate the effect of the various heavy metals on the growth and P removal capacity of Pseudomonas sp., which was well known as phosphorus accumulating microorganism(PAO's) in the EBPR(Enhanced Biological Phosphorus Removal) process. The five heavy metals used in the study were Cu, As, Zn, Ni, and Cd. The growth rate of Pseudomonas sp. was the greatest at $25^{\circ}C$, but the removal efficiency of P was the highest at $30^{\circ}C$. The $IC_{50}$ (median Inhibition Concentration) values of Pseudomonas sp. for the Cu, As, Zn, Ni, and Cd were 2.35, 11.04, 1.80, 4.92, and 0.24 mg/L, respectively. Therefore, it appears that the sensitivity of the heavy metals to Pseudomonas sp. was in the following order: Cd> Zn> Cu> Ni> AS. Also, the P removal efficiencies by Pseudomonas sp. were correspondingly decreased as the concentrations of heavy metals were increased.

• Biomolecules & Therapeutics
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• 제17권2호
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• pp.138-143
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• 2009

We have reported previously on a replication incompetent recombinant adenoviral vector, AdLPCD, in which the expression of cytosine deaminase gene (CD) is driven by the tumor-specific L-plastin promoter. AdLPCD vector had been evaluated for its efficacy of chemosensitization of ovarian cancer cells to 5-FC. In spite of the fact that ovarian cancer cells, i.e., OVCAR-3 and SK-OV-3, are capable for adenoviral transduction judged by LacZ reporter gene analysis, two cell lines demonstrated quite different sensitivities toward AdLPCD/5-FC system. In OVCAR-3 cells, infection of AdLPCD followed by exposure to 5-FC resulted in the suppression of cell growth with statistical significance. On the other hand, SK-OV-3 cells were more resistant to the CD/5-FC strategy compared with OVCAR-3 cells under the same condition. The object of study was to investigate factors that would determine the sensitivity to AdLPCD/5-FC. We evaluated conversion rate of 5-FC to 5-FU after infection of AdLPCD by HPLC analysis, $IC_{50}$ of 5-FU, the expression level of integrin receptors i.e., ${\alpha}v{\beta}3$ and ${\alpha}v{\beta}5$, and status of p53 in OVCAR-3 and SK-OV-3 cells. The results indicated that OVCAR-3 cells have few favorable features compared with SK-OV-3 cells to be more effective to the AdLPCD/5-FC strategy; higher level of ${\alpha}v{\beta}5$ integrin, higher rate of conversion of 5-FC into 5-FC, and lower $IC_{50}$ of 5-FU. The results suggest that the replacement of 5-FU with CD/5-FC in combination chemotherapy would be less toxic and much greater cytotoxicity than the conventional combination chemotherapy in some patients.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.351-351
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• 2006

The possible interactions between cyclodextrins and biodegradable polyesters were investigated. The hydrophobicity of cyclodextrin could be varied with the methyl substitution of host CD, and the possibility of IC formation and the types of interaction between respective CDs and polyesters were subsequently changed. Further, the effect of cyclodextrins on the morphological change of biodegradable polymer was shown to depend on the degree of IC formation between cyclodextrin and biodegradable polymer as well as on the type of interaction between respective CDs and polyesters. That is, the enhancement and/or the restriction of the crystallization of P(3HB) were observed by the incorporation of various kind of cyclodextrins with different cavity size and hydrophobicity.

• 분석과학
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• 제23권2호
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• pp.155-160
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• 2010

먹는 물 중 bromate의 국내 외 시험방법에 대한 분석 조건을 비교하여 최적 시험조건을 확인하고 ion chromatograph-suppressed conductivity detector (IC-CD)를 사용하여 먹는 샘물 중 bromate 함량을 분석하였다. 시료 전처리를 위해 먹는 샘물 20 mL를 온가드 Ba-, Ag-, H-카트리지 순서대로 통과시키고 마지막에 $0.2\;{\mu}m$ 맴브레인 필터로 여과 하였다. 여과한 시료는 IC-CD에 주입하였으며, 시료 중 bromate는 10~50 mM의 KOH 이동상 및 수산화이온용액 이동상에 적합한 가드 및 분석용 컬럼인 AG 19 및 AS 19에 의해 분리하였다. Bromate의 검정 곡선은 $0.5\sim40\;{\mu}g/L$의 농도 범위에서 $r^2$값이 0.9998로 좋은 직선성을 보였으며, 방법검출한계(MDL) 및 정량한계(LOQ)는 각각 0.1, $0.5\;{\mu}g/L$이었다. 2009년 9월 이후 유통 중인 먹는 샘물 157 개 시료를 분석한 결과, 33 개 시료에서 bromate가 검출되었으며, 검출된 시료의 평균농도는 $2.4\;{\mu}g/L$ 이었다. 측정 농도 범위는 $0.5\sim6.5\;{\mu}g/L$로 모두 국내 먹는샘물 수질기준인 $10\;{\mu}g/L$ 이내였다.

• 한국전산유체공학회지
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• 제7권2호
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• pp.17-24
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• 2002

The transient flow fields in a direct injection engine was analyzed by using the STAR-CD CFD code doting the intake/compression processes. The analyses were focused on the computation grid generation by using the IC3M code which is a pre-developed and especially well adapted for the analyses of internal combustion engine. The results showed that the used grid generation technique was well suited for the flow analyses on any internal combustion engine.