• 분석과학
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• 제8권4호
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• pp.877-880
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• 1995

The determination of fluoride and the nutritious calcium in infusion of teas are explained. Tea leaves were pulverized and were immersed in boiling water. The solution was filtered and fluoride, calcium and oxalic acid were determined by the ion chromatography. The quantities of fluoride, calcium and oxalate ions extracted from 100 g of tea leaves were calculated. Tea leaves were also immersed in 0.5 M hydrochloric acid and extracted oxalate and calcium ions were analyzed. The free oxalic acid and calcium were extracted in boiling water and the total ones were extracted in hydrochloric acid. The quantity of calcium oxalate was calculated from the total and the free oxalic acids. The free calcium was estimated to be nutritious.

• The Korean Journal of Physiology
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• 제16권1호
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• pp.1-11
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• 1982

Force development of smooth muscle cells is directly regulated by the concentration of free calcium ions in the sarcoplasm, and the sarcoplasmic concentration of calcium ion can be modulated by electrogenic Na-K pump. The role of Na-K pump on vascular tone was studied in isolated rabbit renal artery. Helical strips of arterial muscle were prepared from left renal arteries. All experiments were performed in $HCO_3^--buffered$ Tyrode solution which was aerated with $3%CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. In some experiments, rabbit was injected intraperitoneally $18{\sim}24$ hours prior to the experiments, with a large dose(5 mg/kg body wt) of reserpine, in order to eliminate the catecholamines present in intrinsic adrenergic nerve terminate. Treatment used in this experiment that inhibits Na-K pump was the exposure of strips to K-free Tyrode solution. Contractile response to K free Tyrode solution developed slowly and the time required for maximum contracture was $20{\sim}30$ minutes. This K-free contracture was rapidly relaxed by the addition of potassium to the bathing solution. No K-free contracture occurred in a Ca-free Tyrode solution. But contraction developed rapidly when calcium ion was added to the bathing solution after 30 minute exposure of the strip to Ca-free Tyrode solution. This contracture was completely inhibited by Ca-antagonist, verapamil. The K-free contracture was abolished by ${\alpha}-adrenergic$ blocker, phentolamine, as well as by the catecholamine depletion from adrenergic nerve terminals. Even in reserpinized strip, the exogenous norepinephrine-induced contraction in K-free Tyrode solution was rapidly suppressed by the addition of potassium ion. The results of this experiment suggest that K free contracture develops by norepinephrine release from adrenergic nerve terminals, while the relaxation of K-free contracture is induced by the activation of electrogenic Na-K pump.

• KSBB Journal
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• 제11권3호
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• pp.329-339
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• 1996

The effects of ammonium ion on cell growth kinetics, monoclonal antibody productivity, and cell metabolism of hybridoma cells were investigated. The mouse-mouse hybridoma cell line VlIIH-8 producing mouse IgG2a was used as a model system. Ammonium ion showed an inhibitory effect on cell growth and monoclonal antibody production. New immobilized adsorbents were developed for the reduction of the inhibitory effect of ammonium ion. The ammonium ion selective zeolite, Phillipsite-Gismondine was entrapped in calcium alginate bead or in dialysis membrane and applied to the hybridoma cell culture system for the in situ removal of ammonium ion from culture media. The effects of ammonium the both serum supplemented and serum free media on the cell growth were studied by applying immobilized adsorbents of calcium alginate bead type. The results demonstrated a substantial enhancement in cell growth. Applying immobilized adsorbents of dialysis membrane type to serum supplemented media also resulted in the stimulation of cell growth, cell viability and monoclonal antibody production.

• 한국수산과학회지
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• 제42권5호
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• pp.456-460
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• 2009

Biofilm is a structured community of microorganism encapsulated within a self-developed polymeric matrix and adherent to a living or a solid surface. In this study, we investigated the effects of various substrates on the formation of biofilm in Vibrio parahaemolyticus. We found that biofilm formation profoundly increased in a substrate, that consisted of calcium chloride, calcium nitrate, and calcium sulfate in 1% peptone water. On the other hand, a dramatic reduction in biofilm formation was observed in a substrate, that consisted of glucose and ferric chloride in LB broth. These results suggest that V. parahaemolyticus prefer to form a biofilm on the surface of a crustacean or a clam, where calcium ion is rich, and also where seawater temperature is relatively lower. In contrast, high levels of glucose in a crustacean or a clam body resulting from increased seawater temperature, can make V. parahaemolyticus detach from it and lead to free floating.

• Journal of Plant Biology
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• 제36권4호
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• pp.321-326
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• 1993

Sugar uptake is accompanied with H+-substrate-symport generally. Both H+/sugar-and H+/K+ stoichiometries during the sugar-uptake have been reported to be exactly 1 : 1. This paper reports that the stoichiometries were enhanced dramatically by the addition of CaCl2 into the medium and by the high cell density of 200 $\mu$L pc/mL. The concentration of free Ca2+ ions in the cells increased significantly with cell density. It is suggested that the free Ca2+ ions are responsible for the change of stoichiometry of sugar transport system by regulation of H+ ion level of biomembrane.

• 대한치과보철학회지
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• 제45권6호
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• pp.795-804
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• 2007

Statement of problem. Nano-scale calcium-phosphate coating on the anodizing titanium surface using ion beam-assisted deposition (IBAD) has been recently introduced to improve the early osseointegration. However, not much is known about their surface characteristics that have influence on tissue-implant interaction. Purpose. This study was aimed to investigate microtopography, surface roughness, surface composition, and wettability of the titanium surface modified by the anodic oxidation and calcium phosphate coating using IBAD. Material and methods. Commercially pure titanium disks were used as substrates. The experiment was composed of four groups. Group MA surfaces represented machined surface. Group AN was anodized surface. Group CaP/AN was anodic oxidized and calcium phosphate coated surfaces. Group SLA surfaces were sandblasted and acid etched surfaces. The prepared titanium discs were examined as follows. The surface morphology of the discs was examined using SEM. The surface roughness was measured by a confocal laser scanning microscope. Phase components were analyzed using thin-film x-ray diffraction. Wettability analyses were performed by contact angle measurement with distilled water, formamide, bromonaphtalene and surface free energy calculation. Results. (1) The four groups showed specific microtopography respectively. Anodized and calcium phosphate coated specimens showed multiple micropores and tiny homogeneously distributed crystalline particles. (2) The order of surface roughness values were, from the lowest to the highest, machined group, anodized group, anodized and calcium phosphate deposited group, and sandblasted and acid etched group. (3) Anodized and calcium phosphate deposited group was found to have titanium and titanium anatase oxides and exhibited calcium phosphorous crystalline structures. (4) Surface wettability was increased in the order of calcium phosphate deposited group, machined group, anodized group, sandblasted and acid etched group. Conclusion. After ion beam-assisted deposition on anodized titanium, the microporous structure remained on the surface and many small calcium phosphorous crystals were formed on the porous surface. Nanoscale calcium phosphorous deposition induced roughness on the microporous surface but hydrophobicity was increased.

• 공업화학
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• 제5권3호
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• pp.406-412
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• 1994

Water glass로부터 ${\delta}-Na_2Si_2O_5$를 합성하여, 이의 칼슘과 마그네슘의 이온교환성, 이온교환에 대한 열역학적 특성치를 조사하였다. Water glass로부터 합성한 ${\delta}-Na_2Si_2O_5$의 최적 합성온도가 $725^{\circ}C$ 근처임을 알았다. 이온교환반응에 있어서 마그네슘 이온교환능이 칼슘 이온교환능보다 우수하였고, 마그네슘의 이온교환능은 온도에 민감하지 않은 반면에, 칼슘의 이온교환능은 온도에 민감하여 온도증가에 따라 이온교환능의 증가폭이 큼을 알 수 있었다. 초기 수용액 pH 변화에 따른 칼슘과 마그네슘의 이온교환능은 초기 수용액 pH가 2~6 사이에서 약간 감소하였으나, 6 이상에서는 ${\delta}-Na_2Si_2O_5$의 알카리 완충효과 때문에 각각 일정하게 나타났다. 이온교환 Gibbs 자유에너지는 이온교환 선택성의 역순으로 칼습 이온 교환반응이 마그네슘 이온교환반응보다 높게 나타났으며, 엔탈피와 엔트로피값도 칼슘 이온교환반응이 마그네슘 이온교환 반응보다 높게 나타났다.

• 대한수의학회지
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• 제31권1호
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• pp.123-130
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• 1991

The present study was performed to investigate the effect of Ca ion concentration on sperm viability and acrosome reaction rate and to evaluate the effect of treatments using caffeine and Ca-ionophore A23187 on acrosome reaction rate in frozen-thawed bull spermatozoa. Viabilities of in vitro capacitated bull spermatozoa at 0, 2.25 and 4.5 mM Ca ion concenrations were 21.00, 26.00 and 22.59%, respectively and significantly higher in Ca ion 2.25mM added group than Ca ion free group (p<0.05) and acrosome reaction rates of in vitro capacitated bull spermatozoa were 17.09, 52.15 and 47.92%, respectively and significantly high in Ca ion added groups(p<0.05). Viabilities in vitro capacitation by caffeine and Ca-ionophore A23187 in control, caffeine treated group, Ca-ionophore A23187 treated group and caffeine+Ca-ionophore A23187 treated group were 37.91, 27.67, 22.33 and 25.59%, respectively and significantly higher in control than treated groups(p<0.05), there were no significant differences among the treated groups, and acrosome reaction rates were 10.33, 37.92, 48.09 and 57.17%, respectively and there were significant differences among the groups(p<0.05), especially higher in caffeine+Ca-ionophore A23187 treated group than others.

• 한국토양비료학회지
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• 제47권5호
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• pp.351-355
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• 2014

In recent years, biochar has received much attention as soil amendment, enhancing soil fertility and reducing toxicity of heavy metals with its large specific surface area and high pH. Biochar has also the effect of alleviating global warming by carbon sequestration from recycling organic wastes by pyrolysis. However, scattering of fine particles of biochar is a hindrance to expand its use from human health point-of-view. Alginate, a natural polymer without toxicity, has been used for capsulation and hydrogel fabrication due to its cross-linking nature with calcium ion. In this study, the method of cross-linkage between alginate and calcium ion was employed for making dust-free biochar bead. Then an equilibrium adsorption experiment was performed for verifying the adsorption effect of biochar bead on heavy metals (cadmium, copper, lead, arsenic, and zinc). Results showed that biochar bead had effects on adsorbing heavy metals, especially lead, except arsenic.

• 한국발생생물학회지:발생과생식
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• 제12권3호
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• pp.267-274
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• 2008

포배의 분화는 배아의 착상에 있어 핵심적인 단계로 배아 자체 또는 생식수관에서 유래하는 조절요인의 조절을 받는다. 이들 조절요인과 포배와의 순차적인 신호의 주고 받음은 분화의 중요한 단계로 인식되고 있다. 한편, 포배기 때 자유 칼슘을 통한 신호전달경로가 포배의 분화에 중요한 축의 하나로 제안되어 왔다. Concanavalin A(Con A)가 포배의 자유 칼슘 농도 증감을 유도한다는 것을 밝혀졌으나, 포배 내 자유 칼슘 농도를 변형시켜 부화와 그 이후의 발생을 촉진하는 것으로 알려진 heparin-binding epidermal growth factor-like growth factor(HB-EGF)와는 달리 팽창 이후의 부화를 억제하였다. 따라서 본 연구에서는 착상과정에서 중요한 역할을 하는 것으로 알려진 prostaglandin $E_2(PGE_2)$가 포배의 분화에 관여하는지를 Con A와 연계하여 알아보았다. Con A는 그 처리 시간에 관계없이 1시간 처리군 그리고 계속처리군에서 팽창은 촉진하고 부화는 유의하게 억제하였다. 특히 계속처리군에서 부화율이 1시간 처리군에 비하여 유의하게 감소하였다. 또한, $PGE_2$도 포배 내 자율 칼슘 농도를 증가시켰으나 팽창과 부화를 촉진하지 않았다. 또한, $10{\mu}m\;PGE_2$ 농도에서는 부화가 억제되는 경향을 보였다. 그러나 흥미롭게도 $PGE_2$는 Con A가 처리된 포배의 부화를 촉진하였다. Con A를 전처리한 포배에 $PGE_2$를 처리할 경우 포배 내 자유 칼슘의 농도 증감이 진행됨을 공촛점현미경을 이용하여 분석할 수 있었다. 이러한 결과는 신호물질에 의해 유도된 자유 칼슘 농도의 증감이 신호물질에 따른 각기 다른 칼슘 매개로 활성화되는 신호경로를 조절하는 것을 추정할 수 있다. 또한, 순차적 신호물질 조절에 의한 자유 칼슘의 농도 증감이 포배의 분화에 있어 중요함을 제안한다.