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Competitive Growth and Attachment of Listeria monocytogenes and Lactococcus lactis ssp. lactis ATCC 11454

  • Lee, Shin-Ho;Frank, Joseph-F.
    • Journal of Microbiology and Biotechnology
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    • 제2권2호
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    • pp.73-77
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    • 1992
  • The effect of a nisin-producing Lactococcus lactis spp. lactis (L. lactis) on the growth and attachment of Listeria monocytogenes Scott A and Brie 1 on stainless steel and their growth in Brain Heart Infusion broth was determined. Viable cells of Listeria decreased rapidly after 9~12 hr of incubation at $21^{\circ}C$ and after 6~9 hr of incubation at $32^{\circ}C$ in the presence of L. lactis. The number of L. monocytogenes Scott A attached to stainless steel in pure culture was $2.5{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.3{\times}10^3/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ after 48 hr of incubation, but was only $10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}1.1{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$ in the presence of L. lactis. Results from L. monocytogenes strain Brie 1 were similar to those from strain Scott A. The population of L. monocytogenes Scott A which attached to stainless steel with previously adherent L. lactis was $1.8{\times}10^2/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}8.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, whereas the population attached to sterile stainless steel was $1.2{\times}10^3/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}2.1{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. For L. monocytogenes Brie 1, the attached population of the control was $1.6{\times}10^4/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}3.2{\times}10^2/\textrm{cm}^2{\;}at{\;}32^{\circ}C$, and on stainless steel with adherent L. lactis, it was $1.1{\times}10/\textrm{cm}^2{\;}at{\;}21^{\circ}C{\;}and{\;}6.9{\times}10/\textrm{cm}^2{\;}at{\;}32^{\circ}C$. Surface adherent L. lactis was less inhibitory to attachment of L. monocytogenes on stainless steel than a liquid culture inoculum. Listeria attached to stainless steel survived dry storage for 20 days both in the presence and absence of adherent lactococci.

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원편광기를 이용한 CR 렌즈의 광 탄성 해석 연구 (Anaysis of the photoelastic of CR lens using circular polariscope)

  • 김용근
    • 한국안광학회지
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    • 제6권2호
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    • pp.11-16
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    • 2001
  • 렌즈에 가한 응력을 측정하기 위한 편광기는 1/4 파장판-편광판으로 구성하였고, 각 단계별 광파의 $E_1$, $E_2$의 성분을 분석하였다. 주 응력차 ${\sigma}_1-{\sigma}_2$는 무늬 차수(N)가 시료 각 점에서 분석되고, 시료의 광축은 주 응력 방향과 일치하는 것으로부터 2 차원 모델을 결정할 수 있다. 광파에 작용하는 복굴절성과 위상지연은 주 응력차 (${\sigma}_1-{\sigma}_2$)에 비례하고, 최종 광파의 세기는 $sin^2({\Delta}/2)$에 비례하고, ${\Delta}/2=n^{\pi}$ (n=0, 1, 2, ...)일 때 소멸 무늬인 흡광이 일어난다. 실험적 결과로는 렌즈의 외부 응력의 크기에 따라 흡광 band가 이동한다.

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Dysregulation of NRF2 in Cancer: from Molecular Mechanisms to Therapeutic Opportunities

  • Jung, Byung-Jin;Yoo, Hwan-Sic;Shin, Sooyoung;Park, Young-Joon;Jeon, Sang-Min
    • Biomolecules & Therapeutics
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    • 제26권1호
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    • pp.57-68
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    • 2018
  • Nuclear factor E2-related factor 2 (NRF2) plays an important role in redox metabolism and antioxidant defense. Under normal conditions, NRF2 proteins are maintained at very low levels because of their ubiquitination and proteasomal degradation via binding to the kelch-like ECH associated protein 1 (KEAP1)-E3 ubiquitin ligase complex. However, oxidative and/or electrophilic stresses disrupt the KEAP1-NRF2 interaction, which leads to the accumulation and transactivation of NRF2. During recent decades, a growing body of evidence suggests that NRF2 is frequently activated in many types of cancer by multiple mechanisms, including the genetic mutations in the KEAP1-NRF2 pathway. This suggested that NRF2 inhibition is a promising strategy for cancer therapy. Recently, several NRF2 inhibitors have been reported with anti-tumor efficacy. Here, we review the mechanisms whereby NRF2 is dysregulated in cancer and its contribution to the tumor development and radiochemoresistance. In addition, among the NRF2 inhibitors reported so far, we summarize and discuss repurposed NRF2 inhibitors with their potential mechanisms and provide new insights to develop selective NRF2 inhibitors.

CaO.MgO.$2 SiO_2-Al_2O_3$계의 고용체의 결정구조 (Structure Refinements of Solid Solutions in the System CaO.MgO.2 $2 SiO_2-Al_2O_3$)

  • 안영필;김복희
    • 한국세라믹학회지
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    • 제23권5호
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    • pp.25-34
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    • 1986
  • This study was to refined the crystal structure of solid solution to determine the position and amount of Al in diopside and to relate crystal structure changes and properties of solid solution. Single crystals of the solid solution in the system CaO.MgO.$2 SiO_2-Al_2O_3$ were made from the melt with slow cooling and used to refine the structure. The following were obtained. 1. Tetrahedra rotated around axis parallel to the direction which the angle 03-03-03 became small. 2. Tetrahedron became large and regular. Average T-O bond distance increased 0.53 percent. 3. M1 octahedron became small and average M1-O bond distance decreased 1.1 percent. 4, M2 polyhedron became small and average M2-O bond distance decreased 0.37 percent Polythedron was affected not so much compared with any cation site. 5. Distance between metal ions distances between T and oxygens which were coordinated with M2 and meighboring tetrahedron distances between M2 and oxygens which coordinated with M1 and M2 were not changed almost. 6. $Al^{3+}$ substituted 4Mg^{2+}$ and $Si^{4+}$

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P2P 스트리밍 서비스를 위한 지연시간 보장 오버레이 네트워크 (A Delay-guaranteed Overlay Network for P2P Streaming Service)

  • 박승철
    • 한국IT서비스학회지
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    • 제9권3호
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    • pp.83-93
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    • 2010
  • P2P streaming technology has advantages of scalability and availability comparing to the popular IP multicast. This paper proposes an approach to apply the P2P streaming technology to the delay-sensitive multimedia multicast applications. In order for the P2P streaming to be applied to the delay-sensitive applications, prior construction of delay-guaranteed overlay network is necessarily required. Moreover, the delay-guaranteed overlay network should be able to be kept even when the hand-overs occur owing to the departures of the intermediate P2P peers. This paper proposes a delay-guaranteed overlay network construction method by using the bandwidth and end-to-end delay based admission control and the backup peer based hand-over control mechanism.

발효사료의 생산에 관한 연구 2 (Studies on the Production of Fermented Feed (2))

  • 배정설;박윤중;이석건;이택수
    • 미생물학회지
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    • 제9권1호
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    • pp.32-38
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    • 1971
  • In solid culture of Endomycopsis fibuliger No.55, Eudomuopsis javanensis No.112 and Candida tropicalis No.340, the conditions of enzyme (protease, anylase and cellulase) production and the influence of addition of $(NH_4)_2;SO_4$ were examined, and the results obtained were as follows. 10 Wheat bran medium is found to be the best on the enzyme production in case of simple material. The optimum conditions ; are water content added 100 to 120%, temperature 25 to $80^{\circ}C$ and incubation times 2 to 3 days. 2) The cellulase production was scarely produced in the case of Endomyopsis fibuliger No.55, as well as, the amylase production was scarely producted in the case of Endomycopsis javanensis No.112 and Candida tropicalis No.340. 3) The enzyme production was remarkably increased when 5% of$(NH_4)_2;SO_4$ as inorganic nitrogen sources was admixed to wheat bran. 4) When 5% of $(NH_4)_2;SO_4$ was admixed to medium, the ratio of protein increase was 10.2 to 17.7% in wheat bran medium and 10.6 to 17.9% in sweet potato cake medium.

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caAdapter에 기반 한 V2-V3 변환 도구 개발 (Development of Conversion Tools from V2 to V3 based on caAdapter)

  • 엄기성;김화선;홍해숙;조훈
    • 전기학회논문지
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    • 제59권4호
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    • pp.809-813
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    • 2010
  • Although the goals of HL7 Version 2(V2) and Version 3(V3) are identical, the concepts of the implementation and technological basis are different; this makes their versions inconvertible. This problem interrupts technological innovation advanced from V2 to V3 and has been raised as a new type of barrier in the field of medical information system. This study intends to develop software to convert V2 to V3 which can be utilized in the actual medical environment. Since it is practically difficult to develop the whole tools that automatically change total V2 messages into V3 messages, this article has designed, implemented, and tested the software that allows mapping between V2 and V3 which function as tools. In order to test this program, it has used ADT^A03 of five V2 messages to generate V3 messages. It is expected that the result of this research will be one of the new methods allowing conversion between V2 and V3.

$PGF_2\alpha$ 투여가 초산돈의 혈중 Progesterone 농도와 발정재귀일수에 미치는 영향 (Effect of $PGF_2\alpha$ on the Serum Progesterone Level and Interval from Weaning to Estrus in Primiparous Sow)

  • 연정웅;김정우
    • 한국가축번식학회지
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    • 제18권2호
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    • pp.127-131
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    • 1994
  • In order to examine the effects of PGF2$\alpha$ on intervals from weaning to estrus and serum progesterone levels seventeen crossbred primiparious sows were randomly alloted to two groups. One group was injected intramuscularly on the day of weaning with 10 mg PGF2$\alpha$ (10mg/2ml, Lutylase). The other group was treated with saline as a control. Serum progesterone concentrations were determined at 24 hour intervals for 12 days after weaning. A serum progesterone level in PGF2$\alpha$-treated group was reached to the lowest level(1.19$\pm$0.38 ng/ml) on day 3 after weaning and remained low(1.26~1.43ng/ml) thereafter. Whereas, the control group showed the lowest level of progesterone on day 4 after wearing, then showed a rapid increase up to 5.02$\pm$0.38ng/ml on day 8 and a rapid decrease was followed. The PGF2$\alpha$ treated group showed an interval from weaning to estrus(5.2$\pm$0.8 days) approximately 2 days shorter than the control(7.4$\pm$3.0 days)(p<0.05).

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Diffusion barrier characteristics of molybdenum nitride films for ultra-large-scale-integrated Cu metallization (I); Surface morphologies and characteristics of sputtered molybdenum nitride films

  • Jeon, Seok-Ryong;Lee, You-Kee;Park, Jong-Wan
    • Journal of Korean Vacuum Science & Technology
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    • 제1권1호
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    • pp.24-29
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    • 1997
  • Surface morphologies and fundamental characteristics of molybdenum nitride films deposited by reactive dc magnetron sputtering were studied for application to Cu diffusion barrier. A phase transformation from Mo to $\gamma$-Mo$_2$N phase at 0.5$N_2$ flow ratio.($N_2$/(Ar+$N_2$)) equal to and larger than 0.2, whereas a second phase transformation to $\gamma$-MoN phase at 0.5 N2 flow ratio, With the variation of the N2 ratio the surface morphologies of the films were generally smooth except the cases of 0.2 and 0.3$N_2$ gas rations, where build-up of film stresses occurred. $\gamma$-Mo$_2$N film was found to crystallize at the deposition temperature of 40$0^{\circ}C$. The surfaces of $\gamma$-Mo$_2$N films deposited up to 40$0^{\circ}C$ were smooth, but the film deposited at 50$0^{\circ}C$ had very rough surface morphology. It seems that this was due to the building-up of thermal stresses at the high deposition temperature, which might lead to hillock formation.

구리(Cu) 노출에 따른 전복, Haliotis discus hannai의 생체축적 및 성장의 변화 (Bioaccumulation and growth change in the abalone Haliotis discus hannai exposed to copper)

  • 박희주;강주찬
    • 한국어병학회지
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    • 제25권2호
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    • pp.103-109
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    • 2012
  • The objective of this study was to investigate the effects of exposured $Cu^{2+}$ on growth and bioaccumulation of abalone Haliotis discus hannai. Abalone were exposed to various concentration of $Cu^{2+}$ (0, 5, 10, 20, $40{\mu}g/L$). Bioaccumulation of tissues, hepatopancreas, muscles and gills were measured. hepatopancreas and gills $Cu^{2+}$ concentration of abalone increases to extent during the 4 weeks accumulation time. But muscles showed no significant changes, with respect to control. These data indicate that abalone Haliotis discus hannai hepatopancreas and gills can be considered adequate target tissues for waterborne exposured of $Cu^{2+}$. Weight growth rate of abalone exposed to $Cu^{2+}$ was significantly decreased in 20 and $40{\mu}g/L$ groups compared to control. This study revealed that high $Cu^{2+}$ concentration (${\geq}20{\mu}g/{\ell}$) reduced growth of abalone. These data indicate that excessive waterborne $Cu^{2+}$ can affect the toxicity of xenbiotics to abalone through alterations in growth rate. Thus, environmental standard of $Cu^{2+}$ $20{\mu}g/L$, should be considered a potential source of variation in toxicological studies with abalone.