• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.95-95
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• 1998

• 원예과학기술지
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• 제29권5호
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• pp.433-440
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• 2011

본 실험은 수경재배 방식으로 본엽 2매까지 키운 양상추를 이용하여 NaCl 스트레스(0, 50 및 100mM NaCl)에 의한 생체중과 건물중, 항산화 물질 및 무기이온 함량 의 변화를 조사하였다. 양상추 유묘의 생체중 및 건물중은 NaCl의 농도 증가에 따라 증가하였으며, 50mM NaCl 처리시 가장 높았다. Chl a, total Chl 함량과 Chl a/b는 100mM NaCI 처리 후 6일째 증가하였으나, Chl b 함량은 감소하였다. 100mM NaCl 처리 후, 총글루타치온 함량은 양상추 유묘의 뿌리에서 증가하였으나, 총아스코르빈산은 뿌리와 줄기에서 모두 증가하였다. 또한, NaCl 스트레스에 의한 spermidine 감소 현상과 spermine 증가현상을 나타내었다. 게다가, 뿌리 및 줄기에서 $Na^+$ 함량이 증가함에 따라 $K^+$, $Ca^{2+}$ 및 $Mg^{2+}$ 함량은 감소하였으며 $K^+/Na^+$, $Ca^{2+}/Na^+$ 및 $Mg^{2+}/Na^+$ ratio 역시 감소하였다. 종합해보면, 이들 결과는 양상추 유묘에서 NaCl 처리에 의해 산화 스트레스가 유도되고, 그 결과 산화 스트레스에 대응하기 위한 대사과정의 변화로 판단된다.

• 분석과학
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• 제11권6호
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• pp.448-451
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• 1998

납사 그랙킹 공정과정에서 사용되는 caustic 농도와 부산물로 형성되는 $Na_2CO_3$, $Na_2S$ 농도를 신속하고 정확하게 분석할 수 있는 검량법의 개발과 근적외선 분광기의 적용가능성에 대하여 연구하였다. 주성분 회귀분석을 이용한 검량법과 근적외선 분광기의 조합은 현재 사용되고 있는 습식 적정법의 대체 분석법으로 빠르고 비파괴적으로 적용 가능한 기기이며, 0.1 표준예측오차의 정밀한 분석을 할 수 있다.

• 대한한의학회지
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• 제17권2호
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• pp.264-276
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• 1996

This study was carried out to evaluate the effect of Samhwasan on the Na-K-ATPase activity of heart muscle. The Na-K-ATPase activity was prepared from rabbit heart ventricles. Samhwasan markedly inhibited the Na- K - ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.56%. Hill coefficient was 1.70, indicating that the enzyme has more than one binding site for the Samhwasan. Inhibition of enzyme activity by Samhwasan increased as pretreatment time was prolonged. Inhibition by the drug was not affected by a change in enzyme protein concentration. Kinetic studies of substrate activation of the enzyme indicated classical noncompetitive inhibition, showing significant reduction in Vmax without a change in Km value. Inhibitory effect by Samhwasan was not altered by changes in concentration of $Mg^{2+}$, $Na^+$ or $K^+$, dithiothreitol. a sulfhydryl reducing reagent, did not protect the inhibition of Na-K-ATPase activity by Samhwasan combination of Samhwasan and ouabain showed a cumulative inhibition fashion. These results suggest that Samhwasan inhibits Na-K-ATPase activity of heart ventricles with an unique binding site different from that of ATP, $Mg^{2+}$, $Na^+$ or $K^+$ and ouabain.

• Korean Chemical Engineering Research
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• 제48권3호
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• pp.322-326
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• 2010

수소발생용으로 사용되는 $NaBH_4$ 수용액의 저장과정 중에 $NaBH_4$ 안정성에 대해 연구하였다. $NaBH_4$의 안정성을 증가시키기 위해 NaOH와 KOH를 사용하였으며, $NaBH_4$의 저장 중 가수분해반응에 미치는 알칼리와 $NaBH_4$ 농도, 온도 그리고 저장 용기 재질의 영향을 실험하였다. 알칼리농도가 증가할수록 $NaBH_4$가 수용액 중에서 안정화되기 때문에 수소발생 속도가 감소하였다. $NaBH_4$ 농도를 10에서 15 wt%로 증가시켰을 때 안정성이 감소하다 15 wt% 이상으로 농도를 증가시켰을 때는 pH의 증가에 의해 안정성이 증가하였다. $NaBH_4$ 농도를 25 wt%, NaOH 3.0 wt%일 때 수소발생 활성화 에너지 값은 115.1 kJ/mol 로 촉매를 사용했을 때보다 활성화 에너지 값이 1.5~4.0배 높았다. 유리나 스텐리스-스틸에 저장된 $NaBH_4$ 용액의 안정성이 플라스틱에 저장된 $NaBH_4$ 용액의 안정성보다 더 높았다.

• 한국환경농학회지
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• 제24권3호
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• pp.232-237
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• 2005

This study was conducted to elucidate the effects of NaOH fusion treatment on Na-P1 zeolite synthesis from fly ash and to evaluate its optimal condition. NaOH fusion treatment of fly ash led to Na-P1 zeolite with shorter reaction time and higher quality compared that of simple hydrothermal method. Mixed zeolite phases of Na-P1 and hydroxy sodalite were formed by the fusion treatment below $450^{\circ}C$, whereas only Na-P1 zeolite was formed above $550^{\circ}C$. Ratio of NaOH/fly ash, reaction times, fusion temperature and solid/liquid ratio strongly affected the kind and crystallinity of the zeolite formed. The CEC of Na-P1 zeolite formed at the optimum reaction conditions of NaOH/fly ash ratio 0.9 and solid/liquid ratio $1/5.0{\sim}1/7.5$ after NaOH fusion treatment at $550^{\circ}C$ for 2 hours was about $398cmol^+kg^{-1}$ which was 40% higher than those of control products. Therefore, it is clear that NaOH fusion treatment of fly ash in open system could lead to Na-P1 zeolite with high purity.

• 대한의용생체공학회:의공학회지
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• 제39권4호
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• pp.161-167
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• 2018

Polyvinyl alcohol/sodium carboxymethyl cellulose (PVA/NaCMC) hydrogels were prepared by physical crosslinking (cyclic freezing/thawing) and gamma (${\gamma}$)-ray irradiation to evaluate the effect of NaCMC concentration (2~8 wt%) on the mechanical properties and the biocompatibility of the PVA/NaCMC hydrogels. The swelling rate of PVA/NaCMC hydrogels regardless of irradiation rose with increasing NaCMC content from 2 wt% to 8 wt%, while the gelation rate was the reverse. As the NaCMC content increased from 2 wt% to 6 wt%, the compressive strength of the hydrogels increased dramatically from $8.5{\pm}2.0kPa$ to $52.7{\pm}2.5kPa$ before irradiation and from $13.5{\pm}2.9kPa$ to $65.5{\pm}8.7kPa$ after irradiation. When 8 wt% NaCMC was added afterwards, the compressive strength decreased however. The irradiated PVA/NaCMC hydrogels containing 6 wt% NaCMC exhibited the tailored properties of the swelling rate of $118{\pm}3.7%$, the gelation rate of $71.4{\pm}1.3%$, the strength of $65.5{\pm}8.7kPa$, respectively, and no cytotoxicity was observed.

• 대한한의학회지
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• 제16권1호통권29호
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• pp.281-294
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• 1995

The effect of Sam Hwa San on the Na-K-ATPase activity was evaluated in microsomal fraction prepared from rabbit cerebral cortex to determine whether Sam Hwa San affects Na-K-ATPase activity of nervous system. Sam Hwa San markedly inhibited the Na-K-ATPase activity in a dose-dependent manner with an estimated $I_{50}$ of 0.12%. Optimal pH for the Na-K-ATPase activity was at 7.5 in the presence or absence of Sam Hwa San. The degree of inhibition by the drug more increased at acidic and alkalic pHs than neutral pH. Kinetic studies of substrate and cationic activation of the enzyme indicate classic noncompetitive inhibition fashion for ATP, Na and K, showing significant reduction in Vmax without a change in Km. Dithiothreitol, a sulfhydryl reducing reagent, partially protects the inhibition of Na-K-ATPase activity by Sam Hwa San. Combination of Sam Hwa San and ouabain showed higher inhibition than cumulative inhibition. These results suggest that Sam Hwa San inhibits Na-K-ATPase activity in central nervous system by reacting with, at least a part, sulfhydryl group and ouabain binding site of the enzyme protein, but with different binding site from those of ATP, Na and K.

• The Korean Journal of Physiology
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• 제7권1호
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• pp.41-47
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• 1973

$Na^{+}$ balance was studied in Rana temporaria, which hibenates in fresh water in the winter time. $Na^{+}$ uptake rate, skin $Na^{+}$ loss rate, urinary $Na^{+}$ loss rate and $Na^{+}-K^{+}$ adenosine triphosphatase(ATPase) were measured at two different temperatures $1{\sim}2^{\circ}C\;and\;20{\sim}24^{\circ}C$ respectively. The results obtained were as follows: 1. $Na^{+}$ uptake rates in the frog in an artificial Pond water (APW) were found to be $8.28{\pm}0.73\;and\;2.19{\pm}0.37\;{\mu}Eq/g/day\;at\;20{\sim}24^{\circ}C\;and\;1.0{\sim}2.5^{\circ}$ respectively. 2. $Na^{+}$ loss rate through the frog skin to APW were found to be $4.26{\pm}0.72\;and\;0.93{\pm}0.21\;{\mu}Eq/g/day$ at the same temperatures. 3. Mean rates of urinary $Na^{+}$ loss at $20{\sim}24^{\circ}C\;and\;3{\sim}4^{\circ}C$ were found to be $3.02{\pm}0.73\;and\;0.78{\pm}0.13\;{\mu}Eq/g/day$ respectively. 4. The activities of $Na^{+}-K^{+}$ activated ATPase of frog skin fragments were found to be $258{\pm}39.4\;and\;49.6{\pm}7.1\;{\mu}M\;Pi/g$ protein/hr at $24^{\circ}C\;and\;2^{\circ}C$ respectively. From the above results, it may be concluded that frogs can take up enough $Na^{+}$ through the skin from APW exceeding skin loss Plus urinary loss at $1{\sim}2^{\circ}C$. It is suggested that $Na^{+}$ transport across frog skin is closely related with $Na^+-K^+$ ATPase since $Q_{10}\;of\;Na^{+}$ uptake is much similar to that of the activities of $Na^{+}-K^{+}$ ATPase.

• 생물환경조절학회지
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• 제26권2호
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• pp.133-139
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• 2017

본 연구는 NaCl 및 jasmonic acid(JA) 처리 시 스피아민트(Mentha spicata)의 생육 및 생리적 반응 변화를 조사하고자 실시하였다. 대조구, JA($20{\mu}M$ JA 전처리), JA+NaCl($20{\mu}M$ JA 전처리+ 50mM NaCl), NaCl(50mM NaCl) 처리 등 4처리구로 구분하여 0.5배 Hoagland 용액에서 3주간 수경 재배한 후 생장반응과 엽록소, 비타민 C, 프롤린, 무기물, DPPH 라디칼 소거 항산화 활성 등을 측정하였다. 스피아민트의 초장, 엽장, 엽폭 및 생체중은 대조구에 비해 모든 처리구에서 감소하였고, 특히 NaCl 처리구에서 현저히 감소하였다. 반면에 건물중은 JA+NaCl 혼용처리구를 비롯하여 모든 처리구에서 증가하였다. 엽록소 a와 b 함량은 JA 처리구가 가장 높았으나 비타민 C와 항산화 활성 및 지상부의 프롤린 함량은 염 스트레스로 생육이 가장 낮았던 NaCl 처리구에서 가장 높게 나타났다. 이온 흡수의 균형 정도를 알 수 있는 K/Na 비율은 JA 단독 처리 시 증가하였고, NaCl처리 및 JA+NaCl 혼용 처리구에서는 $Na^+$ 흡수 증가로 인하여 K/Na 비율이 낮아졌다. 이러한 결과는 낮은 염 스트레스나 JA처리 같은 적절한 스트레스 처리가 항산화 활성과 정유를 포함하는 이차대사물질의 축적을 유도함으로써 스피아민트의 품질을 향상시킬 잠재적인 가능성을 보여준다.