• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.104-104
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• 2001

Ras는 세포의 성장과 분화 등 여러 필수적인 세포기능에 없어서는 안될 중요한 역할을 담당하며 Ras가 mutation되면 암 등의 치명적인 결과를 초래한다. Ras 발현은 유방암에서 tumor aggressiveness의 지표로 간주되고 있으며 유방세포의 침습성과 연관이 있다고 알려져 있으므로 ras가 전이과정에 미치는 영향에 관한 연구는 중요한 의미를 갖는다. 본 연구의 선행연구결과, H-ras와 N-ras 모두 transformed phenotype을 나타내지만 H-ras 만이 암전이에 있어서 중요한 침윤성을 유도하는 것을 밝혔다. 이 결과는 MCF10A 세포에서 H-ras와 N-ras에 의한 신호전달경로가 각각 다른 생물학적 전이활성을 나타냄을 시사한다. 세포의 이동성은 침습성에 있어서 결정적인 역할을 하므로, 본 연구에서 H-ras와 N-ras로 형질전환된 MCF10A세포에서 이동성을 시험한 결과, 세포의 이동성이 N-ras가 아닌 H-ras MCF10A 세포에서만 크게 증가된다는 것을 보았다. 이는 침습성을 나타내는 H-ras가 세포의 이동성을 증가시키는데 작용한다는 것을 말한다. H-ras에 의해 유도된 침습성과 이동성에 대한 분자적 기전에 관하여 연구하기 위하여 H-ras MCF10A와 N-ras MCF10A 세포에서 Ras의 downstream effector들, 특히 mitogen-activated protein kinases(MAPKinases)들인 JNK1, ERK, p38의 활성화를 살펴본 결과 p38 MAPKinase가 H-ras MCF10A 세포에서 현저하게 활성화됨을 보았다. p38 MAPKinase 저해제인 SB203580를 처리하던지 dominant negative p38 (DN p38) transfectant로 p38을 불활성화시켰을 때 세포침습성 및 이동성이 저해되는 결과를 얻었다. SB203580 처리한 H-ras MCF10A 세포에서 전이에 관여하는 효소인 MMP-2 분비가 감소되었다. H-ras에 의해 유도된 침습성과 이동성은 DN JNK1 transfectant에서는 변화가 없었으나 DN MEK transfectants에서는 유의성있게 감소되었다. 이상의 결과를 종합하면, MCF10A 세포의 침윤성과 이동성에는 p38 MAPKinase 활성이 중심적인 역할을 하며, JNK 활성은 영향을 미치지 않고, ERK-1/2 활성은 충분하지는 않으나 필요하다는 것을 알 수 있었다.

• Korean Chemical Engineering Research
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• v.54 no.3
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• pp.419-424
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• 2016

$H_5PMo_{10}V_2O_{40}$ ($PMo_{10}V_2$) catalyst chemically immobilized on sulfur-containing mesoporous carbon (S-MC) was prepared, and it was applied to the benzyl alcohol oxidation reaction. S-MC was synthesized by a templating method using SBA-15 and p-toluenesulfonic acid as a templating agent and a carbon precursor, respectively. S-MC was then modified to have a positive charge, and thus, to provide sites for the immobilization of $PMo_{10}V_2$. By taking advantage of the overall negative charge of $[PMo_{10}V_2O4_{40}]^{5-}$, $PMo_{10}V_2$ catalyst was immobilized on the S-MC support as a charge matching component. It was revealed that $PMo_{10}V_2$ species were finely and molecularly dispersed on the S-MC via chemical immobilization. In the vapor-phase oxidation of benzyl alcohol, $PMo_{10}V_2$/S-MC catalyst showed higher conversion of benzyl alcohol and higher yield for benzaldehyde and benzoic acid than unsupported $PMo_{10}V_2$ catalyst. The enhanced catalytic performance of $PMo_{10}V_2$/S-MC was due to fine dispersion of $PMo_{10}V_2$ species on the S-MC via chemical immobilization.

• ETRI Journal
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• v.30 no.2
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• pp.261-267
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• 2008

In this paper, we propose and demonstrate a cost-effective technique to upgrade the capacity of dense wavelength division multiplexing (DWDM) networks to a 40 Gb/s line rate using the existing 10 Gb/s-based infrastructure. To accommodate 40 Gb/s over the link optimized for 10 Gb/s, we propose applying a combination of super-FEC, carrier-suppressed return-to-zero, and pre-emphasis to the 40 Gb/s transponder. The transmission of 40 Gb/s DWDM channels over existing 10 Gb/s line-rate long-haul DWDM links, including $40{\times}40$ Gb/s transmission over KT's standard single-mode fiber optimized for 10 Gb/s achieves successful results. The proposed upgrading technique allows the Q-value margin for a 40 Gb/s line rate to be compatible with that of 10 Gb/s.

• Applied Microscopy
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• v.52
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• pp.9.1-9.5
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• 2022

The compact smooth muscle 10S myosin II is a type of a monomer with folded tail and the heads bending back to interact with each other. This inactivated form is associated with regulatory and enzymatic activities affecting myosin processivity with actin filaments as well as ATPase activity. Phosphorylation by RLC can however, shuttle myosin from the inhibited 10S state to an activated 6S state, dictating the equilibrium. Multiple studies contributed by TEM have provided insights in the structural understanding of the 10S form. However, it is only recently that the true potential of Cryo-EM in deciphering the intramolecular interactions of 10S myosin state has been realized. This has led to an influx of new revelations on the 10S inactivation, unfolding mechanism and association in various diseases. This study reviews the gradual development in the structural interpretation of 10S species from TEM to Cryo-EM era. Furthermore, we discuss the utility of Cryo-EM in future myosin 10S studies and its contribution to human health.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.148-148
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• 2013

스퍼터 이온펌프(Sputter Ion Pump)는 주로 화학흡착으로 동작하며 기계적 진동이 없고, 기름 등의 오염 물질을 배출하지 않으며, 수명이 길어 초고청정 진공이 요구되는 표면실험장치, 표면분석계, 입자가속기 등에서 널리 사용 되고 있다. 일정한 지름을 갖는 다수의 원통 양극과 그 양단에 두개의 음극판을 배치시킨 후, 양극과 음극 사이에 수 kV의 전압을 걸고 원통의 축방향으로 자장을 인가하면 페닝 방전이 발생한다. 냉음극에서 방출된 전자는 양극으로 비행하면서 가스를 이온화한다. 이온분자는 가스흡수성 게터재료로 된 음극에 충돌하여 스퍼터링을 일으키며 게터막를 주변에 증착시킨다. 이온 및 중성 가스는 게터 고체막 속에 주입 포획되는 형태로 배기된다. 스퍼터 이온펌프는 $10^{-5}$ Pa 부근에서 최대 배기속도를 가지며, 압력이 낮아질 수록, 특히 $10^{-10}$ Pa영역 이하에서는 그 배기속도가 급격히 저하되며, $10^{-10}$ Pa영역에서는 배기능력을 거의 상실한다. 따라서 스퍼터 이온펌프 단독으로 진공시스템을 배기할 때 도달압력은 $10^{-9}$ Pa 영역에 머무르게 되며, $10^{-10}$ Pa 이하의 극고진공을 얻기 위해서는, $10^{-8}$ Pa 이하의 압력에서 배기 속도가 압력과 무관한 흡착펌프(getter pump)와 이온펌프를 조합하여 사용한다. 본 실험에서는 $600^{\circ}C$ 이상의 온도로 진공로에서 탈개스시킨 진공용기를 배기속도 450, 60, 30, 20, 5, 3 l/s의 6종류의 이온펌프와 배기속도 400 l/s, 100 l/s의 non-evaporable getter (NEG) 펌프를 조합시켜 배기하여 그 배기 특성을 비교하였다. 도달 압력은 이온펌프의 배기속도가 클수록 낮아지는 경향을 보여주었다. 450 l/s 이온펌프와 400 l/s NEG를 조합하여 배기시킬 때 도달 압력은 ~$2{\times}10^{-10}$ Pa을 기록하여 가장 낮았으며, 3 l/s 이온펌프와 400 l/s NEG를 조합하였을 때는 $ 2{\sim}3{\times}10^{-8}$ Pa을 기록하였다. 450 l/s 이온펌프와 400 l/s NEG를 조합한 경우 잔류가스의 대부분이 수소였으나, 3 l/s 이온펌프와 400 l/s NEG의 조합한 경우에는 메탄의 잔류량이 수소 보다 많았다. 이 결과는 메탄을 배기하지 못하는 NEG의 배기 특성을 보완하기 위해서는 일정 배기속도 이상의 이온 펌프가 필요함을 보여준다.

• Journal of Aquaculture
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• v.9 no.4
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• pp.345-351
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• 1996

Mass production of resting egg of the rotifer, Brachionus plicatilis was carried out in 1 $m^3$ tank for L-type rotifer and in 1 $m^3$ and 4 $m^3$ tank for S-type rotifer. L-type rotifer was fed on concentrated Chlorella + baker's yeast and only baker's yeast for 15 days. S-type rotifer was fed on concentrated Chlorella in 1 $m^3$ tank for 7 days and frozen Chlorella + baker's yeast in 4 $m^3$ for $6\~8$ days. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for L-type rotifer fed on Chlorella + baker's yeast were $54.5{\times}10^6$ eggs, $30.5{\times}10^6$ eggs and $100{\times}10^3$ eggs, respectively. These were higher than those of rotifer fed on baker's yeast only. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for S-type rotifer fed on concentrated Chlorella in 1 $m^3$ tank were $50\~104{\times}10^6$ eggs, $47\~82{\times}10^6$ eggs and $136\~260{\times}10^3$ eggs, respectively. In 4 $m^3$ tank with frozen Chlorella + baker's yeast, these were $149\~567{\times}10^6$ eggs, $36\~123{\times}10^6$ eggs and $131\~338{\times}10^3$ eggs, respectively. This result suggests that S-type rotifer are better than L-type rotifer for the mass production of resting egg of the Korean rotifer.

• Journal of Pharmacopuncture
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• v.10 no.3
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• pp.71-76
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• 2007

Objectives This experimental study was performed to investigate the continuous anti-bacterial potency of Coptidis rhizoma extract on cultivation of Staphylococcus species(S. aureus, S. epidermidis) that induce eye disease. Methods Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$ diluted Coptidis rhizoma extract(100%, 10%, 1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. Anti-bacterial potency was measured by the size of inhibition zone with change of volume($20{\mu}l,\;30{\mu}l,\;40{\mu}l,\;50{\mu}l$). Results 1. Anti-bacterial potency of Coptidis rhizoma extract on S. aureus was appeared in 100%, 10% and was the same as anti-bacterial potency of 2 days and 6 days. Anti-bacterial potency with change of volume(100%) was increased in propotion to increase volume on all samples. Anti-bacterial potency with change of volume(10%) was increased in propotion to increase volume on all samples except $20{\mu}l$. Anti-bacterial potency of Coptidis rhizoma extract on S. aureus was appeared continuous. 2. Anti-bacterial potency of Coptidis rhizoma extract on S. epidermidis was appeared in 100%, 10% and was the same as anti-bacterial potency of 2 days and 6 days. Anti-bacterial potency with change of volume(100%) was increased in propotion to increase volume on all samples. Anti-bacterial potency with change of volume(10%) was appeared in $50{\mu}l$. Anti-bacterial potency of Coptidis rhizoma extract on S. epidermidis was appeared continuous. Conclusions Anti-bacterial potency of Coptidis rhizoma extract on cultivation of S. aureus & S. epidermidis was showed continuous.

• Food Science and Preservation
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• v.22 no.3
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• pp.314-321
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• 2015

This study was conducted to investigate the quality and characteristics of semi-dried persimmons soaked in different concentrations of sugar solution and stored at $7^{\circ}C$ for 20 days. The L value and chroma value were significantly higher in S5 and S10 compared to the other concentrations of sugar solution. The ${\Delta}E$ and browning degree were increased according to the increase in concentration of sugar solution. Total sugar, reducing sugar, and sugar free contents were higher in the control (semi-dried persimmon) than those in S0, but they increased according to the increase in concentration of sugar solution. Polyphenol oxidase and peroxidase activities were decreased according to the increase in sugar solution concentration, which were highest in S0 among other semi-dried persimmons soaked in sugar solutions. Total ascorbic acid content was highest in S10 (12.29 mg/g), followed by S0 (2.54 mg/g), S5 (7.76 mg/g), S15 (6.05 mg/g), and S20 (5.05 mg/g). Total polyphenols, flavonoids and proanthocyanidins contents were the highest in S10 compared to other semi-dried persimmons soaked in sugar solutions. Furthermore, the same tendency was observed with DPPH radical scavenging ability. These results showed that 10% sugar solution could be applied to semi-dried persimmons in order to achieve high quality, nutritional value, and browning inhibition.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.28-34
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• 2006

Laboratory column tests using $Cl^-$ tracer were conducted to study the correlation of soil particle distribution and hydrodynamic dispersion mechanism with three kinds of ununiformed soil samples, in which the ratio of gravel and sand versus silt and clay is 24.5 for S-1 soil, 4.48 for S-2 soil, and 0.4 for S-3 soil. Chloride breakthrough curves with time were fitted with gaussian functions. The relative concentrations of chloride were converged to 1.0 after 0.7 hours for S-1, 6.3 hours for S-2, and 389 hours for S-3. Average linear velocity, longitudinal dispersion coefficient, and longitudinal dispersivity were calculated by chloride breakthrough curves. Longitudinal dispersion coefficients were $1.20{\times}10^{-4}\;m^2/sec$ for S-1, $8.87{\times}10^{-7}\;m^2/sec$ for S-2, and $1.94{\times}10^{-9}\;m^2/sec$ for S-3. Peclet numbers calculated by the molecular diffusion coefficient of chloride and the mean grain diameters of soils were $2.59{\times}10^2$ for S-1, $6.27{\times}10^0$ for S-2, and $1.35{\times}10^{-4}$ for S-3. Mechanical dispersion was dominant for the hydrodynamic dispersion mechanism of S-1. Both mechanical dispersion and molecular diffusion were dominant for the hydrodynamic dispersion mechanism of S-2, but mechanical dispersion was ascendant over molecular diffusion. Hydrodynamic dispersion in S-3 was occurred mainly by molecular diffusion. When plotting three soils on the graph of $D_L/D_m$ versus Peclet number produced by Bijeljic and Blunt (2006), the values of $D_L/D_m$ for S-1 and S-2 were more than 2.0 order compared to their graph. S-3 was not plotted on their graph because the Peclet number was as small as $1.35{\times}10^{-4}$.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.2
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• pp.361-369
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• 2000

Enterococcus is a normal inhabitant of the human oral cavity, the vagina, and the gastrointestinal tract. Four isolates of Enterococcus in this study were identified as E. durans. These bacteria were characterized and the interaction of these bacteria with the important oral bacteria as like S. mutans and S. oralis was studied as follows. 1. The carbohydrate fermentation test and biochemical test showed similar results in 4 isolates. 2. The susceptibility test against erythromycin, penicillin, tobramycin, ampicillin, teicoplanin, ciprofloxacin, vancomycin, gentamicin, kanamycin, and streptomycin showed to be susceptible in all four isolates. 3. The optical density of absorbance at 550 nm was 1.405 in the culture of S. mutans in disposable cuvette, whereas being 0.855, 0.867, 0.797, and 1.083 in the combined culture of S. mutans and each E. durans. 4. The mean weight of produced artificial plaque on the wires in the beaker was $1566{\pm}103mg$ in culture of S. mutans only, whereas being reduced to $44{\pm}5mg,\;41{\pm}12mg,\;34{\pm}7mg,\;and\;38{\pm}12mg$ in the combined culture of S. mutans and each E. durans. The viable cells were $2.0\times10^9$ per ml in the culture of S. mutans wheras being $2.0\times10^7\;to\;6.0\times10^7$ per ml in the combined culture S. mutans and E. durans. 5. The viable cells were $2.1\times10^8$ per ml in the culture of S. oralis, wheras being $1.4\times10^7\;to\;7.0\times10^7$ per ml in the combined culture of S. oralis and E. durans. 6. Plasmid of about 60 kb was isolated in three isolates of E. durans. These results suggested that E. durans isolated from the oral cavity inhibited the replication of S. mutans and formation of artificial plaque, while inhibiting the replication of S. oralis a little.