• Journal of Ginseng Research
• /
• 제30권2호
• /
• pp.57-63
• /
• 2006

One of the various signaling agents in the animal cells is the simple ion called calcium, $Ca^{2+}$.$Ca^{2+}$ controls almost everything that animals do, including fertilization, secretion, metabolism, muscle contractions, heartbeat, learning, memory stores, and more. To do all of this, $Ca^{2+}$ acts as an intracellular messenger, relaying information within cells to regulate their activity. In contrast, the maintenance of intracellular high $Ca^{2+}$ concentrations caused by various excitatory agents or toxins can lead to the disintegration of cells (necrosis) through the activity of $Ca^{2+}$-sensitive protein-digesting enzymes. High concentrations of calcium have also been implicated in the more orderly programs of cell death known as apoptosis. Because this simple ion, acts as an agent for cell birth, life and death, to coordinate all of these functions, $Ca^{2+}$ signalings should be regulated precisely and tightly. Recent reports have shown that ginsenosides regulate directly and indirectly intracellular $Ca^{2+}$ level with differential manners between neuronal and non-neuronal cells. This brief review will attempt to survey how ginsenosides differentially regulate intracellular $Ca^{2+}$ signaling mediated by various ion channels and receptor activations in neuronal and non-neuronal cells.

• 한국대기환경학회지
• /
• 제14권4호
• /
• pp.361-368
• /
• 1998

Acid rainwater samples were collected during 4 years from 1992 in Pusan area nearby seaside. Ionic composition of early and succeeding rainwater were investigated to identify emission sources. pH and Electronic Conductivity of samples were measured immediately after sampling. Major ion concentrations of rain samples were Na+, Ca2+, Mg2+, K+, NH4+, SO42-, NO3-, Cl- which were analyzed by ion Chromatography. 55% of early rainwater and 90% of succeeding rainwater were identified below pH 5.6. Because, Na+, K+, Ca2+ were washed mostly in early rainwater, as a result, pH values were increased by increasing rainfall amounts. It was studied that pH value was varied from ambient ion component, rainfall, and rain intensity. From the principal component analysis result, the dominant components of acid rainwater were Na+, K2+, Mg2+, Ca2+, the elements were contributed soil and marine source, the second components nuts -SO42-, SO4a-, NO3-, nuts -Ca2+ originated from man - made source.

• 식품기술
• /
• 제18권2호
• /
• pp.52-58
• /
• 2005

최근 20여년 동안 Panax ginseng의 다양한 효과가 연구 되어져 왔다. Panax ginseng의 주요 활성 성분인 ginsenosides는 오직 인삼에서만 발견되어지는 saponin이다. 최근 들어 신경, 非신경 또는 복합적으로 분포된 세포에서 ginsenoside가 $Ca^2+$, $K^+$,$Na^+$,$Cl^-$ channel이나 ligand gated ionchannel (5-HT3, nicotinic acetylcholine, NMDA receptor)과 같은 다양한 ion channel을 조절하는증거들이 발표되고 있다. Ginsenoside는 voltage-dependent $Ca^2+$, $K^+$,$Na^+$ channel의 활성을 억제하는 반면 $Ca^2+$-activated $Cl^-$ channel이나 $Ca^2+$-activated $K^+$ channel의 활성은 증가 시키는 것으로 나타났다. 또한 흥분성 ligand-gated ion channel인 $5-HT_3$, nicotinic acetylcholine, NMDA receptor의 활성은 억제한다. 본 총설에서는 현재까지 알려진 ion channel 활성에 대한 ginsenoside의 조절작용과 이것으로 인해 어떻게 생물학적 효능과 연결이 되어있는지에 대하여 이야기하고자 한다.

• 한국세라믹학회지
• /
• 제23권1호
• /
• pp.7-12
• /
• 1986

Dielectric properties of $Ba_{0.9}Ca_{0.1}(Ti_{1-x}Sn_x)O_3$ were investigated from x=0 to 0.20, and temperature range -4$0^{\circ}C$~13$0^{\circ}C$ Density and grain size decreased with increasing Sn content due to grain growth inhibitor. Dielectric constant below the Curie temperature increased with increasing Sn content and dissipation factor dec reased. These results are due to grain size effect and internal stress. Curie temperature was shifted to lower temperature with increasing ratio of total polarizability to volume resulting from substitution of $Ba^{2+}$ ion with $Ca^{2+}$ ion $Ti^{4+}$ ion with $Sn^{4+}$ ion.

• 멤브레인
• /
• 제19권3호
• /
• pp.189-193
• /
• 2009

제올라이트 분리막 제조 시 제올라이트 골격 내에 존재하는 $Na^{+}$ 양이온을 $K^{+}$ 이온과 $Ca^{2+}$ 이온으로 교환하여 보다 효율적인 물/에탄올 혼합물로부터 물의 분리를 도모하고자 하였다. NaA형 제올라이트 분리막을 각각의 0.5 M KCI $CaCl_2$, $80^{\circ}C$ 수용액에서 4시간 동안 이온교환 하였다. $Na^{+}$ 이온을 $K^{+}$ 이온으로 교환한 결과, 이온 교환 전 총 투과플럭스는 $900\;g/m^2{\cdot}hr{\sim}2,500\;g/m^2{\cdot}hr$이었으나 이온 교환 후 $600\;g/m^2{\cdot}hr{\sim}2,000\;g/m^2{\cdot}hr$ 정도로 낮아졌으며, 이온 교환 전 $600{\sim}2,200$의 선택도를 나타내던 분리막의 선택도가 이온 교환 후에 $850{\sim}2,500$까지 높아짐을 확인하였다 또한, $Na^{+}$ 이온을 $Ca^{2+}$ 이온으로 교환한 결과, 제올라이트 분리막의 전체 투과플럭스와 선택도 모두 이온 교환 전 후 유사한 결과 값이 나타남을 확인하였다. 따라서 친수성 제올라이트 분리막의 유효세공경을 제어하고 적절한 크기로 조절하여 유기물/물 혼합물 분리에 활용한다면 보다 효과적인 유기물의 선택적 분리가 가능할 것으로 판단된다.

• 한국환경과학회지
• /
• 제22권12호
• /
• pp.1651-1660
• /
• 2013

The adsorption of lithium ion onto zeolite was investigated depending on contact time, initial concentration, cation forms, pH, and adsorption isotherms by employing batch adsorption experiment. The zeolite was converted into different forms such $K^+$, $Na^+$, $Mg^{2+}$, $Ca^{2+}$, and $Al^{3+}$. The zeolite had the higher adsorption capacity of lithium ion in $K^+$ form followed by $Na^+$, $Ca^{2+}$, $Mg^{2+}$, and $Al^{3+}$ forms, which was in accordance with their elctronegativities. The lithium ion adsorption was explained using the Langmuir, Freundlich, and Dubinin-Radushkevich adsorption isotherms and kinetic models. Adsorption rate of lithium ion by zeolite modified in $K^+$ form was controlled by pseudo-second-order and particle diffusion kinetic models. The maximum adsorption capacity obtained from Langmuir isotherm was 17.0 mg/g for zeolite modified in $K^+$ form. The solution pH influenced significantly the lithium ions adsorption capacity and best results were obtained at pH 5-10.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
• /
• pp.30-32
• /
• 2005

The effects of mole ratio and Ti-ion on the dielectric properties and microstructure of modified $CaZrO_3$ composition such as $(Ca_{0.7}Sr_{0.3})_m(Ti_yZr_{1-y})O_3$ were investigated. Ti ions substituted on Zr-sites in these modified $CaZrO_3$ composition strongly affect the sintering density and microstructure of the fired ceramic body. With increasing the amount of Ti substituted on Zr-sites, the sintered density rapidly increased and the dense microstructures were obtained for the compositions having mole ratio of 1.01, whereas the sintered density and microstructures are nearly constant with the content of Ti-ion for the compositions having mole ratio of 0.99. With increasing the content of Ti ion, the curve of TCC (temperature coefficient of capacitance) as a function of temperature rotated clockwise and satisfied the COG characteristics for both of compositions with mole ratio of 0.99 and 1.01. The content of Ti ion seems to be more effective than mole with respect to the controlling of firing and TCC.

• 한국결정학회지
• /
• 제13권1호
• /
• pp.25-30
• /
• 2002

M/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O (M = Ca and Sr) 고용체계는 치환형과 틈새형 고용체를 동시에 갖는다. 이상의 고용체계 물질에 첨가된 발광원자의 에너지 전이는 발광원자, Eu 주위의 대칭성에 깊은 관계가 있다 Eu/sup 3+/ 이온의 경우, Eu/sup 3+/ 이온의 주변 대청성에 따라서 매우 밝고 효율적인 발광성 불순물이 될 수 있기 때문에 구조와 연계한 연구가 가능하다. Eu/sup 3+/: Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O 고용체계의 Na원자 양이 증가함에 따라 Eu3+ 이온의 대칭성이 낮아진다. CaAl₂(BO₃)₂O 화합물은 Ca 원자 중심의 팔면체 구조를 갖기 때문에, 조성비 x의 증가와 함께, 화합물의 낮은 대청성에 의해서 Eu/sup 3+/:Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O 고용체계의 /sup 5/D/sub 0/→/sup 7/F₁(590 nm) 전이의 상대적인 세기가 감소한다. 그러한 또 다른 예는 비대칭성 물질인 Eu/sup 3+/:SrAl₂(BO₃)₂O 화합물에서도 찾아 볼 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제10권2호
• /
• pp.109-114
• /
• 2005

Ion fluxes across the plasma membrane activated by 1 mM $Ce^{4+}$, cell apoptosis and taxol biosynthesis in suspension cultures of Taxus cusp/data were studied. The extracellular pH sharply decreased upon the addition of 1 mM $Ce^{4+}$, then increased gradually and exceeded the initial pH value over a time period of 12 h. The extracellular $Ca^{2+}$ concentration decreased within the first 3 h after the addition of $Ce^{4+}$, then gradually decreased to one third of initial value in control at about 72 h and remained unchanged afterwards. Experiments with an ion channel blocker and a $Ca^{2+}$-channel blocker indicated that the dynamic changes in extracellular pH and the $Ca^{2+}$ concentration resulted from the $Ce^{4+}$-induced activation of W uptake and $Ca^{2+}$ influx across the plasma membrane via ion channels. A pretreatment of the ion channel blocker initiated $Ce^{4+}$-treated cells to undergo necrosis, and the prior addition of the $Ca^{2+}$-channel blocker inhibited $Ce^{4+}$-induced taxol biosynthesis and apoptosis. It is thus inferred that W uptake is necessary for cells to survive a $Ce^{4+}$-caused acidic environment and is one of the mechanisms of $Ce^{4+}$-induced apoptosis. Furthermore, the $Ca^{2+}$ influx across the plasma membrane mediated both the $Ce^{4+}$-induced apoptosis and taxol biosynthesis.

• 공업화학
• /
• 제2권3호
• /
• pp.270-278
• /
• 1991

게 껍질로부터 단리한 천연고분자인 chitin을 이용하여 특정금속이온에 대하여 높은 선택성을 갖는 carboxymethyl chitin을 합성하였다. 실험에 사용된 chitin 은 개량한 Hackman 법으로 순수한 상태로 제조하고 이를 여러농도의 수산화나트륨 용액으로 akali chitin을 제조한 후, chitin 단위구조의 C-6 위치($CH_2OH$)를 isoproryl alcohol 중에서 monochloroacetic 로 처리하여 카르복시기를 갖는 유도체를 합성하였다. Kjeldahl 법에 의한 질소함량의 분석 및 원소분석에 의해 최적반응조건과 치환율을 구하였고, 이들 수지의 구조는 적외선흡수스펙트럼으로 확인하였다. 낮은 치환도를 가지며 물에 불용인 carboxymethyl chitin은 알칼리 토금속이온들 중 $Ca^{2+}$ 이온에 대하여 가장 높은 선택적 흡착능을 나타내었으며, 이러한 성질은 $KNO_3$나 $NaNO_3$와 같은 중성염이 존재할 때에도 마찬가지였다. Carboxymethyl chitin에 결합된 $Mg^{2+}$ 이온은 $Ca^{2+}$이온이 있는 곳에서 방출되며, 이러한 $Ca^{2+}$및 $Mg^{2+}$ 이온 혼합계를 이용하였다. 합성된 흡착담체는 $Ca^{2+}$, $Mg^{2+}$, $Sr^{2+}$, $Ba^{2+}$ 등의 금속이온들과의 흡착특성을 검토하였고, 나아가 $Na^+$, $K^+$등 공통양이온 존재하에서 특정금속이온의 선택적 흡착능을 atomic absorption spectrometer로 정량, 확인하였다.