• Korean Journal of Community Nutrition
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• v.1 no.1
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• pp.71-78
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• 1996

This study was conducted to compare the dietary factors which influence on the bone status of 28 women in urban and 30 women in rural area. Urinary excretion of hydroxyproline(Hpr) and Calcium(Ca) were measured as biological markers of bone resorption. Mean daily intake levels of total protein, animal protein, total calcium, calcium, calcium from milk and milk products, animal calcium, Ca / P ratio by 24 hr recall method were significantly higher in urban women. However, mean daily sodium(Na) intake levels were not significantly different between two groups. Ca Index score and Na Index score by food frequency methods were also significantly higher in urban than in rural subjects. While urinary Ca excretion elves of two groups were similar, Na excretion levels were significantly higher in rural women. Mean urniary levels of Ca / creatinine(cr) and Hpr / cr as bone status index were within normal range and not significantly different between two groups. However, prevalence of poor bone status as assessed by hydroxyproline was higher in rural women. Na Index, urinary Ca excretion and Ca / cr ratio were significantly correlated with bone status(Hpr / cr) in urban women, while only age was related to bone status in rural women. These demonstrated that high Na intake results in increased urinary excretion of Na and Ca and could cause bone resorption. Multiple regression analysis indicated that Na Index score and age have greater effect than other variables in urban women and only age has greater effect in rural women.

• Korean Journal of Crystallography
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• v.13 no.1
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• pp.25-30
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• 2002

The M/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O (M = Ca and Sr) solid solution systems have been shown interstitial solid solutions and continuous substitutional solid solutions. The symmetry around the Eu site of yEu/sup 3+/ : M/sub 1-x/Na/sub 2x/Al/sub 2-y/Mg/sub /(BO₃)₂O (M = Ca and Sr) changes the intensities and the chromaticities of transitions. The Eu/sup 3+/ion can be very bright and efficient and have the desired emission wave-length depending on the site symmetry of the Eu/sup 3+/ion site. As the amount of Na in the Eu/sup 3+/ion doped Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O system increases, the Eu site symmetry is going to be a noncentrosymmetric site. With increasing x, the decreased intensity in the /sup 5/D/sub 0/→/sup 7/F₁(590 nm) transition relates to the low symmetry of the Eus/up 3+/-doped Ca/sub 1-x/Na/sub 2x/Al₂(BO₃)₂O system, because of the Ca-centered octahedron in the CaAl₂(BO₃)₂O compound. The SrAl₂(BO₃)₂O compound also provides an improved chromaticity due to the lower site symmetry of Eu/sup 3+/ion.

• The Korean Journal of Physiology
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• v.26 no.1
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• pp.55-68
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• 1992

The effects of changes in extracellular $Na^+\;and\;Ca^+$ concentration on the membrane potential and contractility were studied in the antral circular muscle of guinea pig stomach in order to elucidate the existence and the nature of $Na^+/Ca^{2+}$ exchange mechanism. All experiments were performed in tris buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C.$ The treatment of $10^{-5}$ ouabain was performed to induce intracellular $Na^+$ loading prior to the start of experiment. The results were as follows: 1. $Na^+$-free Tyrode or high $Ca^{2+}$-Tyrode solution hyperpolarized the membrane potential and induced contracture. The time course of contracture was similar to that of change in membrane potential. 2. The degree of hyperpolarization and the amplitude of contracture decreased in accordance with the increase of extracellular $Na^+$ concentration. 3. $Na^+$-free contracture was developed even after blocking the influence of intrinsic nerves by the pretreatment with atropine, guanethidine and TTX. 4. $Ca^{2+}$-channel blockers(D-600 or $Mn^{2+}$) and the blocker of intracellular $Ca^{2+}$ release from sarcoplasmic reticulum(ryanodine) did not suppress the development of $Na^+$-free contracture. And also, dinitrophenol had no effect on $Na^+$-free contracture. 5. Dose-response relationship between extracellular $Na^+$ concentrations and the magnitude of contractures showed a sigmoid pattern. The slope of straight line from Hill plot was 2.7. 6. In parallel with the increase of extracellular $Ca^{2+}$ concentration, the amplitude of contracture increased dose dependently and was maximum at 8 mM $Ca^{2+}$-Tyrode solution. 7. The relationship between extracellular $Ca^{2+}$ concentrations and the magnitude of contractures showed hyperbolic pattern. The slope of straight line from Hill plot was 1.1. From the above results, it is suggested that $Na^+/Ca^{2+}$ exchange mechanism exists in the antral circular muscle of guinea pig stomach and this mechanism affects the membrane potential electrogenically.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.203-206
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• 2000

Calcium carbonate $(CaCO_3)$ bead immobilized with alginate were developed as buffer system to enhance the cultivation efficiency of bifidobacteria. When Bifidobacteriuim longum KCTC 3128 and HLC 3742 were independently cultivated in 2.5-liter fermenter buffered the $CaCO_3$ bead, NaOH, $Na_2CO_3$, and $NH_4OH$. The proliferation of bifidobacteria and their storage stability were higher in culture broth buffered $CaCO_3$ beads than in culture broth buffered with NaOH, $Na_2CO_3$, and $NH_4OH$. Therefore, $CaCO_3$ bead may be useful as a buffer to enhance of the cultivation efficiency and viability of bifidobacteria.

• Journal of Nutrition and Health
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• v.29 no.10
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• pp.1096-1104
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• 1996

This study was performed to evaluate the effect of sodium cholride supplementation on bone metabolism in female rats consuming a low calcium diet. Twenty five female rats were divided into three dietary groups (control Na : 0.1038%, 1% Na : 1.036%, 2% Na : 2.072%). All experimental diets contained 0.27% Ca and were fed to rats with deionized water for 7 weeks. Bone mineral density(BMD) and bone mineral content(BMC) of total body, spine and femur were measured using energy x-ray absorptiometry(DEXA) by small animal software. Then Ca efficiency was calculated from BMD and BMC. Serum Ca, P, Na and urine Ca, P, Na were determined. Urinary pyridinoline, serum ALP were measured to monitor bone resorption. Following 7 weeks, sodium cholride supplemented groups had higher urinary Ca excreteion, urinary pyridinoline, crosslinks value and serum ALP. There was no significant difference in case of serum Ca among all groups. Sodium chloride supplemnted groups had lower Ca effciency of total, spine and femur BMD and BMC than that of control group. In conclusion high salt intake not only increases urinary Ca excretion as urinary Na excretion does but also increase bone resorption and decrease Ca efficiency of each bone. It is been suggested that high salt intake may be harmful for bone maintenance. Therfore, the decrease of salt intake to the level of recommendation would be desirable.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.269-274
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• 2010

The solubility and the physicochemical property (refractive index) in the NaCl-$CaCl_2$-$H_2O$ and KCl-$CaCl_2$-$H_2O$ systems were determined at $50^{\circ}C$ and the phase diagrams and the diagrams of physicochemical property vs composition were plotted. One invariant point, two univariant curves, and two crystallization zones, corresponding to sodium Chloride (or potassium chloride), dihydrate ($CaCl_2{\cdot}2H_2O$) showed up in the phase diagrams of the ternary systems. The mixing parameters ${\theta}_{M,Ca}$ and ${\Psi}_{M,Ca,Cl}$ (M = Na or K) and equilibrium constant $K_{sp}$ were evaluated in NaCl-$CaCl_2-H_2O$ and KCl-$CaCl_2-H_2O$ systems by least-squares optimization procedure, in which the single-salt Pitzer parameters of NaCl, KCl and $CaCl_2$ ${\beta}^{(0)}$, ${\beta}^{(1)}$, ${\beta}^{(2)}$ and $C^{\Phi}$ were directly calculated from the literature. The results obtained were in good agreement with the experimental data.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.107-113
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• 1990

In comparision with calcium sulphate, the effect of calcium-carbonate, -silicate and -hydroxide on desalinization of tidal saline soil was investigated in a continuous leaching column experiments after mixing with an equivalent amount of Ca to sodium plus magnessium in the saline soil. One half of liming materials was mixed to the top one-tenth of column soil and the remainder was spread on the surface. Results obtained are as follows ; 1. Gypsum made easy to percolate and desaline (Na) tidal marine soil but accumulated magnessium in subsoil. 2. $Ca(OH)_2$, $CaCO_3$, and $CaSO_3$ precipitated Mg in the soil which limes were mixed, but they washed down magnessium more severely from the immediate bellow the limed soil and less from the subsequent soil layers. This leaching was more severer at the treatment of $Ca(OH)_2$and lowest at the treatment of $CaSiO_3$. 3. The alkalinity of lime in addition to the dissociation of exchangeable Na raised pH of limed leached tidal soil and slowed down the percolation rate which retarded desalining Na from limed saline soils. This effect was most severe in the $Ca(OH)_2$ treated soil. 4. pH of leached soils was correlated possitively with exchangeable Na and negatively with exchangeable Mg giving follwing relationship pH= 7.77+0.489 Na/Mg r = 0.845.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.1
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• pp.51-57
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• 2010

It was hypothesized that NaF induces calcium sensitization in $Ca^{2+}$-controlled solution in permeabilized rat mesenteric arteries. Rat mesenteric arteries were permeabilized with $\beta$-escin and subjected to tension measurement. NaF potentiated the concentration-response curves to $Ca^{2+}$ (decreased $EC_{50}$ and increased $E_{max}$). Cumulative addition of NaF (4.0, 8.0 and 16 mM) also increased vascular tension in $Ca^{2+}$-controlled solution at pCa 7.0 or pCa 6.5, but not at pCa 8.0. NaF-induced vasocontraction and $GTP{\gamma}S$-induced vasocontraction were not additive. NaF-induced vasocontraction at pCa 7.0 was inhibited by pretreatment with Rho kinase inhibitors H1152 or Y27632 but not with a MLCK inhibitor ML-7 or a PKC inhibitor Ro31-8220. NaF induces calcium sensitization in a $Ca^{2+}$ dependent manner in $\beta$-escin-permeabilized rat mesenteric arteries. These results suggest that NaF is an activator of the Rho kinase signaling pathway during vascular contraction.

• The Korean Journal of Pharmacology
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• v.24 no.2
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• pp.179-187
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• 1988

Verapamil, tetrodotoxin and tetraethylammonium chloride in the stated amount did not affect the $Na^{++}$ induced $Ca^{++}$ release. $Cd^{++}$ and $Zn^{++}$ significantly inhibited the $Na^{++}$ induced $Ca^{++}$ release. $Mn^{++}$ also inhibited $Na^+-Ca^{++}$ exchange. $Cd^{++}$ inhibited $Na^+-Ca^{++}$ exchange noncompetitively with an apparent inhibition constant (Ki) of $100\;{\mu}M$. $Cd^{++}$ caused loss of sulfhydryl group, whereas $Zn^{++}$ did not show any significant effect. $Cd^{++}$ and $Zn^{++}$ effectively inhibited $Na^+-Ca^{++}$ ATPase and slightly inhibited $Ca^{++}-Mg^{++}$ ATPase. Carbonyl cyanide chlorophenylhydrazone, 2,4-dinitrophenol and sodium arsenate stimulated the $Na^{++}$ induced $Ca^{++}$ release. Dibucaine and oligomycin slightly inhibited it. The results suggest that the $Na^+-Ca^{++}$ exchange on the synaptosomal plasma membrane may be not accomplished by ion channels. The $Na^+-Ca^{++}$ exchange is sensitively inhibited by $Cd^{++}$ and this transport process appears to be partially regulated by sulfhydryl groups of the synaptosomal plasma membrane. It is also postulated that $Na^+-Ca^{++}$ exchange is suppressed during the phosphorylation reaction of protein component on the neuronal membrane.

• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.451-457
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• 2018

Luminescence properties of $NaCa(PO_3)_3$ doped with $Tb^{3+}$ ions are investigated by optical and laser excitation spectroscopy. The phosphors were prepared by solidstate reaction method The X-ray diffraction(XRD) was used to analyze the crystal structure and the crystallinity of the samples. The excitation and emission spectra and decay curve of $NaCa(PO_3)_3:Tb^{3+}$(0.01 ~ 30mol%) were measured at room temperature. The f - d band of $Tb^{3+}$ is observed in the excitation spectra of $NaCa(PO_3)_3:Tb^{3+}$ in the wave length region 205 ~ 245 nm. Strong emission lines due to the $^5D_4{\rightarrow}^7F_J$ transition and weak emission lines due to the $^5D_4{\rightarrow}^7F_J$ transition are observed in the emission spectra of $NaCa(PO_3)_3:Tb^{3+}$. The energy transfer and cross relaxation between $Tb^{3+}$ ions are discussed in $NaCa(PO_3)_3:Tb^{3+}$ in the emission spectra and life time.