• Title/Summary/Keyword: M71

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BV CCD PHOTOMETRY OF M71: DISTANCE AND AGE (구상성단 M71의 BV CCD 측광: 거리 그리고 나이)

  • 임홍서;천문석;변용익;손영종
    • Journal of Astronomy and Space Sciences
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    • v.21 no.1
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    • pp.1-10
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    • 2004
  • We present BV CCD photometry of metal-rich globular cluster M71. Based on our color-magnitude diagram (CMD), we derive the distance to M71 using a sample of Hipparcos subdwarfs of similar metallicity. Our distance modulus is (m - M)v = 13.46(${\pm}0.17$. CMD comparison was also made between M71 and 47 Tuc. We confirm that there exists a significant age differonce(> 2 billion years) in spite of their Similarity in metallicity.

Screening of Bacillus sp. No. M-71 with High Alkaline Protease Productivity and Some Properties of the Enzyme (Alkaline Protease 고 생산성 세균의 선별 및 효소 특성)

  • 오성훈;오평수
    • Microbiology and Biotechnology Letters
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    • v.19 no.1
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    • pp.1-7
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    • 1991
  • A bacterial strain No.71, which produced alkaline protease, was isolated from soil and identified to the genus Bacillus. With the successive mutation, a mutant strain No. M-71, having high alkaline protease productivity, was obtanined from the parental strain No 71. Alkaline protease productivity of mutant strain No. M-71 was about 50 times as much as that of the parental strain No.71. The enzyme preparations showed strong activities toward casein, the optimum pH being 11.0 and the optimum temperature about $55^{\circ}C$.

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Stability of Spheroplasts from Saccharomyces cerevisiae D-71 and Zygosaccharomyces rouxii SR-S (Saccharomyces cerevisiae D-71과 Zygosaccharomyces rouxii SR-S로부터 조제한 원형질체의 안정성)

  • 정창기;김찬조;이종수
    • Microbiology and Biotechnology Letters
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    • v.16 no.4
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    • pp.293-296
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    • 1988
  • Stability of spheroplasts prepared from Saccharomyces cerevisiae D-71, a thermophilic strain and Zygosaccharomyces rouxii SR-S, an osmotolerant strain were studied. Stability of spheroplast from Saccharomyces cerevisiae D-71 was highest in 0.8M KCI and 1.0M sorbitol ; that from Zygosaccharomyces rouxii SR-S was highest in 0.4M KCI and mannitol and that from both strains was less than 10% for sonic oscillation at 20Kc for 60 sec. In centrifugation at 10000 x g for 10 min., stability of spheroplast from Saccharomyces cerevisiae D-71 was 93% and that from Zygosaccharomyces rouxii SR-S was 84%. Breakage of spheroplast from Saccharomyces cerevisiae D-71 was 99% and that from Zygosaccharomyces rouxii SR-S was 55% for UV irradiation with 15W UV lamp at a distance of 20 cm for 60 min.

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NEAR-INFRARED PHOTOMETRY OF METAL RICH GLOBULAR CLUSTER M71

  • 경재만;변용익;천문석
    • Journal of Astronomy and Space Sciences
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    • v.14 no.2
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    • pp.194-201
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    • 1997
  • We have carried out JK near-infrared photometry for the central region of the metal rich globular cluster M71, whose (K, J - K) color-magnitude diagram is presented here. Using two independent methods we derive the distance modulus to M71, 12.89 and 12.86 $pm0.12$ respectively. The former is derived using the HB luminosity $M_{Ko}$(HB) = -1.15 for globular clusters having metallicity between -1.0 to -0.3 (Kuchinski et al. 1995). The latter is derived through a comparison with IR photometry of stars in the similar metallicity cluster 47 Tuc. We also estimate the reddening to M71, E(J - K) = 0.13, based on E(B - V) = 0.04 of 47 Tuc.

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A Comparative Analysis for the Performance of 200 N-class Gaseous Methane-Liquid Oxygen Small Rocket Engine According to the Characteristic Length Variation (특성길이 변화에 따른 200 N급 기체메탄-액체산소 소형로켓엔진의 성능 비교 분석)

  • Kang, Yun Hyeong;Ahn, Hyun Jong;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.24 no.6
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    • pp.85-92
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    • 2020
  • Ground hot-firing tests were conducted to analyze the combustion performance according to the characteristic lengths 1.37 m, 1.71 m, and 2.06 m of the combustion chamber in 200 N-class GCH4-LOx small rocket engine. Thrust, specific impulse, and characteristic velocity at the steady-state could be obtained as the key performance parameters of the rocket engine. The performance characteristics acquired through the test were compared and analyzed with the theoretical performance calculated from CEA analysis. Observation of the influence of characteristic length on the combustion performance indicates that an optimal characteristic length shall remain between 1.71 m and 2.06 m.

Inhibitory Effect on Replication of Enterovirus 71 of Herb Methanol Extract

  • Choi, Hwa-Jung;Song, Jae-Hyoung;Ahn, Young-Joon;Kwon, Dur-Han
    • Journal of Applied Biological Chemistry
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    • v.51 no.3
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    • pp.123-127
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    • 2008
  • Anti-enterovirus 71 (EV 71) activities of fifteen herb plant species extracts were examined by SRB assay, among which Origanum vulgare and Rosmarinus officinalis (Anna Rosemary) extracts exhibited the activities with $IC_{50}$ of 8.28 and $8.17\;{\mu}g/mL$, respectively. Their 50% cytotoxicity concentrations ($CC_{50}$) were 691.89 and $1104.19\;{\mu}g/mL$, and the therapeutic indices were 83.56 and 135.15, respectively. Amantadine (positive control) showed anti-EV 71 activity with 50% inhibitory concentration and $CC_{50}$ of 4.46 and $145.22\;{\mu}g/mL$, respectively. Addition of the methanol extracts of O. vulgare and R. officinalis (Anna Rosemary) in EV 71-infected Vero cells strongly inhibited the formation of visible cytopathic effects without changing the normal morphology of the cells. These results indicate that methanol extracts of O. vulgare and R. officinalis (Anna Rosemary) may contain antiviral compound inhibiting the EV 71 replication.

CN AND CH BAND STRENGTH VARIATIONS IN M71 GIANTS

  • LEE SANG-GAK
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.23-31
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    • 2005
  • CN and CH band strengths for fourteen bright giants in the globular cluster M71 have been measured from archival spectra obtained with the Multiple Mirror Telescope. Adding the collected. data from the literature we confirm a bimodality of CN distribution on the red giant branch and the honzontal branch, and CN-CH anti-correlations on the lower giant branch and horizontal branch. However a CN-CH anti-correlation on the upper red giant branch is not quite clear as those of other branches. The small number If statistics could not be excluded as a possible cause. To confirm this, a greater number of sample stars are needed. We also confirm that the ratio of CN-strong to CN-weak stars is quite different from that in 47 Tuc, although the anti-correlation between CN and CH bands, the bimodality of the CN distribution, and the spatial distribution of CN stars in M71 are found to be similar to those III 47 Tuc.

Protoplast Formation and Fusion between Saccharomyces cerevisiae D-71 and Zygosaccharomyces rouxii SR-S (Saccharomyces cerevisiae D-71과 Zygosaccharomyces rouxii SR-S의 원형질체 형성과 융합)

  • 이종수;김찬조
    • Microbiology and Biotechnology Letters
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    • v.16 no.2
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    • pp.142-149
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    • 1988
  • This experiment was carried out to obtain a hybrid with potent ethanol fermenting ability, by means of protoplast fusion between a thermophilic strain (D-71) of Saccharomyces cerevisiae and an osmotolerant strain (SR-S) of Zygosaccharomyces rouxii. The conditions for formation of protoplasts from both strains and for their fusion and regeneration were studied. Favorable conditions for formation of protoplasts from Saccharomyces cerevisiae D-71 were : treatment of the cells at late-exponential phase with 2-mercaptoethanol (l% v/v) for 10 minutes in the presence of 0.5M sorbitol, then incubation for 60 minutes in the set medium containing Zymolyase-20T (4mg/$m\ell$) ; and from Zygosaccharomyces rouxii SR-S were : treatment of the cells at mid-exponential phase with 2-mercaptoethanol (1% v/v) for 10 minutes in the presence of 0.5M or 1M mannitol, then incubation for 120 minutes in the set medium containing Zymolyase-20T(4mg/$m\ell$). The protoplasts of parental cells were fused in the presence of 20mM CaCl$_2$, 0.5M sorbitol and 40% of polyethyleneglycol (M.W 4000), then fusants obtained were selected as regenerated colonies which embedded and grown in the minimal medium containing 3% of agar. The frequencies of fusant formation were 1.2$\times$10$^{-6}$ to 9.1$\times$10$^{-6}$ for the regenerated protoplast.

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Effects of Methionine Diets on the Immunotoxicity of Ethanol in ICR Mice (생쥐에 있어서 에탄올의 면역독성에 미치는 메치오닌 식이의 영향)

  • Ahn, Young-Keun;Kim, Joung-Hoon;Koo, Gi-Bum;Moon, Jae-Gyu
    • YAKHAK HOEJI
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    • v.36 no.4
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    • pp.303-314
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    • 1992
  • Experiments were performed on mice to investigate the effect of methionine diets (MET) on the immunotoxicity of ethanol. ICR female mice were divided into 5 groups, Met (Basal (B)+0.19% methionine(M), B+1.71% M and B+5.13%W) and ethanol(4%) were administered ad libitum for 21 days. The mice were evaluated for changes in immune status as measured by antibody titer, Arthus reaction, delayed type hypersensitivity (DTH), rosette forming cell(RFC) and plaque forming cell (PFC) to sheep red blood cells (S-RBC). To investigate the change of the non-specific immune response, the number of leukocytes in peripheral blood and phagocyte activity were measured. The results were summarized as follows: (1) The weight ratios of spleen and thymus to body weight were significantly increased by the B+0.19% M, B+0.57% M and B+1.71% M groups in comparison with control group(B), but B+5.13% M group was significantly decreased. (2) Humoral immune responses were significantly increased by the B+0.19% M and B+0.57% M groups in comparison with control group, but B+5.13% M group was significantly decreased. (3) Cellular immune responses were significantly decreased by the B+1.71% M and B+5.13% M groups in comparison with control group. (4) Phagocyte activities were significantly increased by the B+0.19% M, B+0.57% M and B+1.71% M groups in comparison with control groups, but B+5.13% M group was significantly decreased. (5) The number of circulating leukocyte was significantly increased in the B+0.19% M and B+0.57% M groups in comparison with control group, but B+5.13% M group was significantly decreased.

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