• Title/Summary/Keyword: L1

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Behavior of Listeria monocytogenes in skin milk during fermentation by Lactobacillus bulgaricus and Streptococcus lactis (Lactobacillus bulgaricus와 Streptococcus lactis 발효탈지유에서의 Listeria monocytogenes의 생존추이)

  • 박경식
    • Journal of environmental and Sanitary engineering
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    • v.12 no.1
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    • pp.85-95
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    • 1997
  • Behavior of Listeria monocytogenes in Skim milk during fermentation by Lactobacillus bulgaricus YI-2 and Streptococcus lactis FYI-1 were determined. Autoclaved skim milk was inoculated with ca. 10$^{3}$ L. monocytogenes (Strain LM91-1 or LM 96-2) cells/ml, and with 5.0, 1.0, 0.5 or 0.1% of a milk culture of either L. bulgaricus TI-2 or S. lactis FYI-1. Skim milk containing ca. 10$^{3}$ L. monocytogenes was incubated at 37 or 42$\circ $C for 15 h with L. bulgaricus YI-2, and at 21 or 30$\circ $C for 15 h with S. lactis FYI-1. Cultured skim milks were stored at 4$\circ $C in the refrigerater. Samples were plated on Oxford Agar with oxford antimicrobic supplement to enumerate L. monocytogenes and on either modified MRS agar to enumerate lactic acid bacteria. L. monocytogenes survived the 15-h fermentation with S. lactis FYI-1 in all combinations of level of inoculum and temperature of incubation, but inhibition of growth ranged from 94 to 100%. When incubated with over the 1.0% of L. bulgaricus, L. monocytogenes inhibited or disappeared in fermented skim milk from 9 h after incubation. Especially, incubation at 42$\circ $C with 5.0% L. bulgaricus YI-2 as inoculum appeared to be the most effective inhibitory combination for strain LM 91-1, causing 100% inhibition in growth based on maximum papulation attained. In most instances of incubated with L. bulgaricus YI-2, growth of the pathogene appeared to be completely inhibited when the pH dropped below 4.38.

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Comparison of Characteristics between $L_1-B_4$ mode and $L_1-B_8$ mode Ultrasonic Motors ($L_1-B_4$모드와 $L_1-B_8$모드 초음파 선형 전동기의 특성 비교)

  • U, Sang-Ho;Kim, Dong-Yeon;Kim, Jin-Soo
    • Proceedings of the KIEE Conference
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    • 2002.07c
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    • pp.1518-1520
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    • 2002
  • Purpose of this research compares best transfer speed about applied frequency and voltage using characteristic of $L_1-B_4$ mode and $L_1-B_8$ mode linear ultrasonic motor that use piezoelectric effect. By method of study, analyzed best transfer speed measuring and comparison load status that use actuality telephone card in $L_1-B_4$ mode linear ultrasonic motor and no-load status of $L_1-B_8$ mode linear ultrasonic motor. Experiment result is applied frequency(58.4Hz) in $L_1-B_4$ mode linear ultrasonic motor (load state) and the best transfer speed by 19.8[cm/s] at applied voltage(56V) point. Also, $L_1-B_8$ mode linear ultrasonic motor (no-load state) is best transfer speed by applied frequency(27.9kHz) and 32.96[cm/s] at applied voltage (50V) point.

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Different Protein Expression between Human Eosinophilic Leukemia Cells, EoL-1 and Imatinib-resistant EoL-1 Cells, EoL-1-IR

  • Sung, Kee-Hyung;Kim, In-Sik;Lee, Ji-Sook
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.426-429
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    • 2018
  • Chronic eosinophilic leukemia (CEL) is characterized by eosinophilia and organ damage. Imatinib is widely used for treating CEL, chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). Unfortunately, the cancer cells gain resistance against the drug after prolonged molecular-targeted therapies. Imatinib-resistant EoL-1 (EoL-1-IR) cells were produced from chronic eosinophilic leukemia cells (EoL-1) after treatment with imatinib for a long duration. Two-dimensional electrophoresis (2-DE) analysis revealed numerous protein variations in the EoL-1 and EoL-1-IR sub-types. Compared to the EoL-1 cells, expression levels of TIP49, RBBP7, ${\alpha}$-enolase, adenosine deaminase, C protein, galactokinase, eukaryotic translation initiation factor, $IFN-{\gamma}$, and human protein homologous to DROER were increased, whereas core I protein, proteasome subunit p42, heterogeneous ribonuclear particle protein, chain B, and nucleoside diphosphate were decreased in the EoL-1-IR cells. Taken together, these results contribute to understanding the pathogenic mechanism of drug-resistant diseases.

Neutralization of Alkaline Wastewater with CO2 in a Continuous Flow Jet Loop Reactor (연속흐름형 Jet loop reactor에서 CO2를 이용한 알칼리폐수의 중화)

  • Kang, Dae-Yeop;Kim, Mi-Ran;Lim, Jun-Heok;Lee, Tae-Yoon;Lee, Jea-Keun
    • Korean Chemical Engineering Research
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    • v.54 no.1
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    • pp.101-107
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    • 2016
  • This paper investigates the feasibility of applying the jet loop reactor for the neutralization of alkaline wastewater using carbon dioxide ($CO_2$). In this study, pH changes and $CO_2$ removal characteristics were examined by changing influent flow rate of alkaline wastewater (initial pH=10.1) and influent $CO_2$ flow rates. Influent flow rates of alkaline wastewater ($Q_{L,in}$) ranged between 0.9 and 6.6 L/min, and inlet gas flow rate ($Q_{G,in}$) of 1 and 6 L/min in a lab-scale continuous flow jet loop reactor. The outlet pH of wastewater was maintained at 7.2 when the ratio ($Q_{L,in}/Q_{G,in}$) of $Q_{L,in}$ and $Q_{G,in}$ was 1.1. However, the $CO_2$ removal efficiency and the outlet pH of wastewater were increased when $Q_{L,in}/Q_{G,in}$ ratio was higher than 1.1. Throughout the experiments, the maximum $CO_2$ removal efficiency and the outlet pH of wastewater were 98.06% and 8.43 at the condition when $Q_{G,in}$ and $Q_{L,in}$ were 2 L/min and 4 L/min, respectively.

Extending the Vase Life of Cut Iris 'Blue Magic' Flowers by 1-Methylcyclopropene (1-Methylcyclopropene 처리에 의한 아이리스 '블루매직'의 절화수명 연장)

  • Kim, Young-A;Lee, Jong-Suk;Park, Jong-Su;Lee, Poong-Ok
    • Horticultural Science & Technology
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    • v.28 no.6
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    • pp.985-989
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    • 2010
  • This experiment was conducted to clarify the effects of 1-methylcyclopropene (1-MCP) on vase life of cut 'Blue Magic' iris. Pretreatment for 4 h with concentrations of 500 nL and 1000 nL 1-MCP, an inhibitor of ethylene action, inhibited the wilting and inrolling response of cut iris. The vase life of iris flowers of 500 nL or 1000 nL 1-MCP treatment was prolonged to 0.5 day compared to those held in distilled water (control). Vase life of iris showed no significant difference between $3{\mu}L{\cdot}L^{-1}$ ethylene exposure after 1-MCP treatment and control. 1-MCP treatment inhibited inrolling and increased fresh weight, water uptake, and water balance. The increase of fresh weight was high in 500 nL 1-MCP treatment and water uptake was increased by 1000 nL 1-MCP. Especially, iris flower without 1-MCP treatment dramatically decreased the water uptake as compared to the control for four or five days. Water balance of iris flowers held in water was changed to minus value faster than those with pretreatment of 1-MCP.

Enhancement of Skin Whitening and Anti-wrinkle Activities of the Co-culture of Lactobacillus rhamnosus and Lactobacillus paracasei (Lactobacillus rhamnosus와 Lactobacillus paracasei 복합 배양의 피부 미백 및 주름 개선 활성 증진)

  • Kim, Nam Young;Lee, Hyeon Yong
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.41 no.3
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    • pp.253-261
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    • 2015
  • In this study, cosmeceutical activities of the co-cultures of both lactic acid bacteria isolated from the hands of women, Lactobacillus rhamnosus (L. rhamnosus) and Lactobacillus paracasei (L. paracasei) were first reported: For whitening and anti-wrinkle activities, the co-culture showed the highest tyrosinase inhibition of 20.68%, compared L. paracasei and L. rhamnosus. The co-culture also showed the highest inhibition of melanin synthesis as 63.7%. In observing the anti-wrinkle activities of the co-culture, it generated only 3726.3 pg/mL of matrixmetalloproteinase-1 (MMP-1) production when 13613.5 pg/mL and 13012.0 pg/mL of MMP-1 production were estimated from L. rhamnosus and L. paracasei. Besides these, the extract from the co-culture yielded higher collagen production as 380.7 ng/mL, compared to 323.4 ng/mL and 304.1 ng/mL from L. paracasei and L. rhamnosus. These results indicate that the co-culture of both lactic acid could improve its cosmetic activities. This hypothesis was also confirmed that the co-culture of both bacteria showed strong antioxidant activities of DPPH free radical scavenging while the extract of L. rhamnosus and L. paracasei.

Production of Citrus Plants from Ovule Cell Culture and Verification of CTV - free Plants (배주배양 세포로부터 감귤 식물체의 획득 및 감귤 트리스테자 바이러스 무병주 검증)

  • Jin, Seong Beom;Park, Jae Ho;Park, Suk Man;Lee, Dong Hoon;Yun, Su Hyun
    • Horticultural Science & Technology
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    • v.35 no.1
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    • pp.121-130
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    • 2017
  • This study was carried out to investigate a method for producing cultured virus - free ovules for breeding high - quality Citrus cultivars. Ovules from the immature fruits of three citrus cultivars native to Jeju (Dongjeongkyool, Cheongkyool, and Jikak) and two cultivars of Citrus unshiu Marc. (Miyagawa wase and Haryejosaeng) that were thought to be infected with Citrus tristeza virus (CTV) were cultured on MS2 medium (Murashige - Skoog [MS] basal medium containing $500mg{\cdot}L^{-1}$ malt extract, $50g{\cdot}L^{-1}$ sucrose, $1.0 mg{\cdot}L^{-1}$ kinetin, and $8g{\cdot}L^{-1}$ agar). After four weeks of culture, 10, 21, 13, 5, and 7 somatic embryos and 2, 4, 2, 4, and 5 white callus cells (surrounding green somatic embryos) were obtained from Dongjeongkyool, Cheongkyool, Jikak, Miyagawa wase, and Haryejosaeng, respectively. After six weeks of culture, somatic embryos were obtained from cultured cells grown on MT basal medium supplemented with malt extract ($500mg{\cdot}L^{-1}$), lactose ($70g{\cdot}L^{-1}$), and agar ($16g{\cdot}L^{-1}$). Over 60% of the somatic embryos from citrus cultivars native to Jeju developed into normal plants on MS basal medium supplemented with malt extract ($500mg{\cdot}L^{-1}$), sucrose ($50g{\cdot}L^{-1}$), and agar ($8g{\cdot}L^{-1}$) after 10 weeks of culture. Normal plants were regenerated from two Citrus unshiu Marc. cultivars on MT basal medium supplemented with sorbitol (1.0 M), galactose (1.0 M), $GA_3$ ($1.0mg{\cdot}L^{-1}$), and Gelrite ($3g{\cdot}L^{-1}$). The absence of virus in plants generated from cultured ovules was confirmed by RT - PCR and antigen - antibody reactions. Therefore, virus - free Citrus cells can be obtained for breeding high - quality citrus cultivars using the biotechnological technique evaluated in this study.

Cloning and Characterization of the Promoters of Temperate Mycobacteriophage L1

  • Chattopadhyay, Chandrani;Sau, Subrata;Mandal, Nitai C.
    • BMB Reports
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    • v.36 no.6
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    • pp.586-592
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    • 2003
  • Four putative promoters of the temperate mycobacteriophage L1 were cloned by detecting the $\beta$-galactosidase reporter expression in E. coli transformants that carried L1 specific operon-fusion library. All of the four L1 promoters were also found to express differentially in the homologous environment of mycobacteria. Of the four promoters, two were suggested to be the putative early promoters of L1 since they express within 0 to 10 min of the initiation of the lytic growth of L1. One of the putative early promoters showed a relatively better and almost identical activity in both E. coli and M. smegmatis. By a sequence analysis, we suggest that the L1 insert that contained the stronger early promoter possibly carries two convergent E. coli $\sigma^{70}$-like L1 promoters, which are separated from each other by about 300 nucleotides. One of them is the early promoter of L1 as it showed a 100% similarity with the early $P_{left}$ promoter of the homoimmune phage L5. The second promoter, designated P4, was suggested for its appreciable level of reporter activity in the absence of the -10 element of the $P_{left}$ equivalent of L1. By analyzing most of the best characterized mycobacteriophages-specific promoters, including the L1 promoter P4, we suggest that both the -10 and -35 hexamers of the mycobacteriophage promoters are highly conserved and almost similar to the consensus -10 and -35 hexamers of the E. coli $\sigma^{70}$ promoters.