• 대한가정학회지
• /
• 제29권2호
• /
• pp.47-53
• /
• 1991

A. niger H-18 and A. fumigatus E-29 wrer selected for their strong abilities to produce cellulase. The λd numerical values of the cotton fabrics inoculated with A. niger H-18 and A. fumigatus E-29 were 580 nm for the both strains of molds. By the growth of molds, lightness, original color scale, and grey scale of the fabrics gradually decreased while chroma increased. The minimum inhibitory concentrations of mold-proofing agents, such as Leperon WL, 8-hydroxyquinoline copper acetate, trimethylol melamine and dimethyl ethylene urea was 50 ppm. Glycoxale was not effective at the above mentioned concentration. Since Leperon WL, trimethylol melamine and dimethyl ethylene urea effectively inhibited the growth of A. niger H-18 and A. fumigatus E-29, tensile strength and elongation of the fabrics were not changed. however, cotton fabrics treated with glycoxale of the fabrics were not changed. However, cotton fabrics treated with glycoxale and inoculated with A. niger H-18 and A. fumigatus E-29 showed decreased in tensile strength by 31.1% and 33.9%, respectively.

• 한국축산식품학회지
• /
• 제32권1호
• /
• pp.62-67
• /
• 2012

This study calculated kinetic parameters of Escherichia coli O157:H7 and developed a probabilistic model to estimate growth probabilities of E. coli O157:H7 on polyethylene cutting boards as a function of temperature and time. The surfaces of polyethylene coupons ($3{\times}5$ cm) were inoculated with E. coli O157:H7 NCCP11142 at 4 Log $CFU/cm^2$. The coupons were stored at 13 to $35^{\circ}C$ for 12 h, and cell counts of E. coli O157:H7 were enumerated on McConkey II with sorbitol agar every 2 h. Kinetic parameters (maximum specific growth rate, Log $CFU/cm^2/h$; lag phase duration, h; lower asymptote, Log $CFU/cm^2$; upper asymptote, Log $CFU/cm^2$) were calculated with the modified Gompertz model. Of 56 combinations (temperature${\times}$time), the combinations that had ${\geq}$0.5 Log $CFU/cm^2$ of bacterial growth were designated with the value of 1, and the combinations that had increases of <0.5 Log $CFU/cm^2$ were given the value 0. These growth response data were fitted to the logistic regression to develop the model predicting probabilities of E. coli O157:H7 growth. Specific growth rate and growth data showed that E. coli O157:H7 cells were grown at $28-35^{\circ}C$, but there were no obvious growth of the pathogen below $25^{\circ}C$. Moreover, the developed probabilistic model showed acceptable performance to calculate growth probability of E. coli O157:H7. Therefore, the results should be useful in determining upper limits of working temperature and time, inhibiting E. coli O157:H7 growth on polyethylene cutting board.

• 동의생리병리학회지
• /
• 제17권2호
• /
• pp.447-450
• /
• 2003

To clerify the cytotoxicity of reactive oxygen species in cultured hippocampal neurons of neonatal mouse, toxic effect was measured by MTT assay after cultured cells were incubated for 3 hours in the media containing 1～40 μM concentrations of H₂O₂. In addition, the protective effect of vitamin E was determined in these cultrures. Cell viability was significantly decreased in a dose-dependent manner after exposure of 10 μM H₂O₂ to cultured mouse hippocampal neurons for 5 hours. In the protective effect of vitamin E, vitamin E prevented the H₂O₂-induced cytotoxicity in these cultures. From these results, it suggests that H₂O₂ has toxic effect in cultured mouse hippocampal neurons and vitamin E has protective effect on the cytotoxicity induced by H₂O₂.

• 대한수의학회지
• /
• 제40권3호
• /
• pp.525-531
• /
• 2000

Verotoxin을 산생하지 않은 Escherichia coli O157과 verotoxin을 산생하는 E coli(VTEC)를 건강한 소의 분변에서 분리하여 생화학적 및 유전적인 특성에 대해서 비교하였다. E coli O157 : nonH7(운동성은 있으나 H혈청형이 7이 아님)의 sorbitol 분해능과 ${\beta}-glucurondase$ 활성은 E coli O157 : H7이 나타내는 것과는 차이가 있었다. 그리고 uidA 유전자는 verotoxin 산생능과 상관없이 sorbitol과 ${\beta}-glucuronidase$ 음성인 E coli O157 : H7에서 특이적으로 검출되었다. 한편 6개 목장에서 수거한 소 분변 45예에서 VTEC를 분리한 결과, 7주(15.6%)가 분리되었으며 이들은 모두 sorbitol을 분해하였으며 ${\beta}-glucurondase$ 활성이 있었으나 장벽 부착인자를 지배하는 eaeA 유전자가 없었다. 비록 소가 VTEC의 보균원으로 추정되나, 정상 소에서 분리한 VTEC는 eaeA 유전자가 결여된 균주가 많으므로 공중위생학상 eaeA 유전자를 보유한 E coli 보다 위해성이 낮으며, 이러한 결과는 왜 사람에서 유행하는 VTEC 혈청형과 소에서 유행하는 것과 차이가 있는지를 일부 설명해준다.

• 대한수학회논문집
• /
• 제30권3호
• /
• pp.313-325
• /
• 2015

An H-magic labeling in a H-decomposable graph G is a bijection $f:V(G){\cup}E(G){\rightarrow}\{1,2,{\cdots},p+q\}$ such that for every copy H in the decomposition, $\sum{_{{\upsilon}{\in}V(H)}}\;f(v)+\sum{_{e{\in}E(H)}}\;f(e)$ is constant. f is said to be H-V -super magic if f(V(G))={1,2,...,p}. In this paper, we prove that complete bipartite graphs $K_{n,n}$ are H-V -super magic decomposable where $$H{\sim_=}K_{1,n}$$ with $n{\geq}1$.

• 한국식품영양과학회지
• /
• 제32권8호
• /
• pp.1239-1244
• /
• 2003

김치의 과숙성을 조절한 고품질화를 위하여 pH 5.0이하의 산성에서 용해되는 Eudragit E100으로 자몽씨 추출물(GFSE)을 함유한 미세 캡슐을 아세톤/액체 파라핀 방법으로 제조하였다. 분산제로 첨가한 aluminium tristearate의 함량에 따라 89.39∼92.13%의 수율을 나타내었으며, aluminium tristearate의 양에 따라 큰 차이를 보이지 않았다. 첨가한 aluminium tristearate함량이 증가할수록 미세캡슐의 크기는 작아지는 경향을 보였는데, 12%의 aluminium tristearate가 존재할 때, GFSE를 함유한 Eudragit E100 미세캡슐은 200 $\mu\textrm{m}$이상이 50.42%, 150∼200 $\mu\textrm{m}$의 범위 내의 것이 36.11%, 100∼150 $\mu\textrm{m}$ 범위의 것이 11.28%, 100 $\mu\textrm{m}$ 이하의 것이 0.17%의 입자 분포를 나타내었다. Eudragit E100 미세 캡슐은 전자현미경으로 구형으로 관찰되었다. Eudragit E100을 pH를 달리한 완충용액에 저장하였을 때, 함유된 GFSE는 pH 3, 4, 5, 6의 조건에서는 1일 만에 내부의 GFSE가 모두 용출되었고 pH 7에서는 9일 후에 약 70%의 GFSE가 용출되었다. 또한, 김치에 첨가하여 저장하였을 때, GFSE 함유 Eudragit E100 미세캡슐의 양이 증가할수록 저장 기간 2일까지는 김치의 pH 저하를 완화시켰으나, 3일 이후에는 큰 영향을 주지 못하였다. 총균수와 젖산균의 경우에서도 GFSE의 첨가량이 증가할수록 각각 감소하는 경향을 나타내었으나 pH에 의한 엄밀한 방출은 관찰되지는 않았다.

• 한국식품위생안전성학회지
• /
• 제12권1호
• /
• pp.78-82
• /
• 1997

Surface swab samples from beef (188), pork (240) and chicken (95) carcasses were collected from slaughterhouse in Kangwon and Kyunggi areas from March through July 1996. The samples were examined on the level of E. coli biotype I relevant to fecal contamination due to unsanitary processing control and the existence of verocytotoxin-producing E. coli (VTEC). E. coli biotype I were confirmed from 38.8% of beef, 40.0% of pork, and 69.5% of chicken carcasses. Little variation was noted among three sampling points; rump, flank and neck of beef, ham, belly and jowls of pork. coli O157:H7 was only confirmed from 2 of 188 beef carcasses. E. coli biotype I. All the isolated E. coli O157 showed positive for vero cell cytotoxicity test. Isolation rate of E. coli O157 in summer was higher than in spring. In case of pork and chicken carcasses, E. coli O157 was isolated in summer only.

• EDISON SW 활용 경진대회 논문집
• /
• 제4회(2015년)
• /
• pp.405-407
• /
• 2015

Graphene의 bandgap이 0eV이고 hBN의 bandgap이 4~5eV라는 이기 때문에 두 물질을 혼합하였을 때 태양전지로 쓰기 좋은 1.2eV의 bandgap을 가지는 물질을 만들 수 있을 거라 생각된다. 이 점을 착안하여 hBN에 Carbon을 도핑시켜 1.2eV의 bandgap을 갖는 물질을 이론적으로 만들어 보았다.

• 한국식품영양과학회지
• /
• 제33권3호
• /
• pp.571-575
• /
• 2004

대장균 O157:H7의 백신 생산을 위해서 purity가 높은 lipopolysacharride 분리, 정제를 위한 실험을 실시하였다. 대장균 O157:H7 균주를 확인하기 위해서 shiga toxin을 생산할 수 있는 60 MDa plasmid를 분리하였고, PCR법에 의해 E. coli O157:H7 shiga-like toxin(Stx) 1, 2의 stx gene을 증폭하여 E. coli O157:H7의 특징 (130 bp, 346 bp)을 확인하였다. E. coli O157:H7 LPS의 분리 정제는 페놀추출, 에탄올 분획 및 gel filtration의 간단한 방법을 사용하였다. 마지막으로 SDS-PAGE와 silver nitrate 염색을 이용하여 LPS의 purity를 확인하였다.

• 상하수도학회지
• /
• 제23권5호
• /
• pp.669-678
• /
• 2009

The reduction of excess activated sludge from petrochemical plant was investigated by the electro fenton (E-Fenton) process using electrogenerated hydroxyl radicals which lead to mineralization of activated sludge to $CO_2$, water and inorganic ions. Factors affecting the disintegration efficiency of excess activated sludge in E-Fenton process were examined in terms of five criteria: pH, $H_2O_2/Fe^{2+}$ molar ratio, current density, initial MLSS (mixed liquid suspended solids) concentration, $H_2O_2$ feeding mode. TSS total suspended solid and $TCOD_{cr}$ reduction rate increased with the increasing $H_2O_2/Fe^{2+}$ molar ratio and current density until 42 and $6.7 mA/cm^2$, respectively but further increase of $H_2O_2/Fe^{2+}$ molar ratio and current density would reduce the reduction rate. On the other hand, as expected, increasing pH and initial MLSS concentration of activated sludge decreas TSS and $TCOD_{cr}$ reduction rate. The E-Fenton process was gradually increased during first 30 minutes and then linearly proceed till 120 minutes. The optimal E-Fenton condition showed TSS reduction rate of 62~63% and $TCOD_{cr}$ (total chemical oxygen demand) reduction rate of 55~56%. Molar ratio $H_2O_2/Fe^{2+} = 42$ was determined as optimal E-Fenton condition with initial $Fe^{2+}$ dose of 5.4 mM and current density of $6.7{\sim}13.3 mA/cm^2$, initial MLSS of 7,600 mg/L and pH 2 were chosen as the most efficient E-Fenton condition.