• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.237-239
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• 1993

$MnO_2$ added $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ was calcined at $850^{\circ}C$ for two hours and sintered at $1100^{\circ}C$ for two hours. The microstructure was examined using XRD and SEM. The dielectric constant, the quality factor, and the temperature stability was measured using Hakki and Coleman method. Dielectric constant was improved to 94 from 0.5wt% $MnO_2$ added sample with $Q{\cdot}f=4260GHz$ and acceptable ${\tau}_f$ (< $20ppm/^{\circ}C$).

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.169-179
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• 1994

The effect of extracellular and intracellular pH on vascular tone and $^{45}Ca$ uptake were investigated in aortic strips and dispersed single aortic smooth muscle cells of spontaneously hypertensive rats (SHR) and aged-matched Wistar-Kyoto rats (WKY). The contraction produced by a change of extracellular pH (pHo) in the range of $6.5{\sim}8.3$ was estimated by comparison with the level of vascular tone at pH 7.4. Contraction was induced below pHo 6.5 in WKY, pHo 7.1 in SHR, and over pHo 8.0 on both strains. The amplitude of contraction induced by high pHo (over pHo 7.7) was similar in SHR and WKY, but that induced by low pHo (below pHo 7.1) in SHR was greater than that in WKY. Either high pHo- or low pHo-induced contractions in WKY and SHR were not induced in the Ca-free Tyrode's solution and were induced by the addition of Ca. $^{45}Ca$ uptake increased progressively as pHo was increased from 6.8 to 8.1 in the single aortic smooth muscle cells of WKY and SHR. $NH_4Cl$ induced a gradually developing contraction in a dose-dependent manner $(5\;mM{\sim}30\;mM)$ and the removal of $NH_4Cl$ induced transient contraction was followed by profound relaxation in the aortic rings of both strains. The contractions induced by $NH_4Cl$ or by the removal of $NH_4Cl$ in SHR were significantly greater than that in WKY. These contractions were not induced in Ca-free Tyrode's solution. $^{45}Ca$ uptake was increased by $NH_4Cl$ (20 mM) and was not changed by the removal of $NH_4Cl$ (20 mM) in the aortic strips of WKY and SHR. As a summary of above results, the vascular tone of SHR was more sensitive to the change pHi and pHo than that of WKY. The contractions induced by change of extracellular or intracellular pH depended on extracellular Ca in the aorta of SHR nnd WKY. However, the Ca uptake was in accord with the changes of contraction but increase in contraction by low pH was not accompanied by an increase in Ca uptake in both strains.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.125-136
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• 1994

To characterize the SR Ca-release channel protein complex of crustacean, $^{45}Ca-release,\;[^3H]ryanodine$ binding, and immunoblot studies were carried out in the crayfish and/or lobster skeletal sarcoplasmic reticulum. Bmax and affinity of crayfish SR to ryanodine were lower than those of lobster SR. AMP (5mM) increased $[^3H]ryanodine$ binding significantly in both vesicles (P<0.05). $Mg^{2+}$(5mM) or tetracaine(1mM) inhibited $[^3H]ryanodine$ binding significantly in both vesicles (P<0.001), but ruthenium red $(10\;{\mu}M)$ inhibited it moderately. In SDS polyacrylamide gel electrophoretic analysis of crayfish SR vesicles, there was a high molecular weight band that showed similar mobility with Ca-release channel protein of lobster skeletal SR, but more rapid mobility (HMWBr) than that of rabbit skeletal SR (HMWBS). Immunoblot analysis showed that polyclonal Ab to lobster skeletal SR Ca-release channel protein was react with HMWBr of crayfish skeletal SR, but not with that of HMWBs of rabbit skeletal SR. ^{45}Ca-release from crayfish skeletal SR vesicles was increased by the increase of extravesicular calcium from $1{\mu}M$ to 1mM. This Ca-release phenomenon was similar, but more sensitive in the low concentration of $Ca^{2+}$, compared to that from lobster SR vesicles. AMP (5mM) or caffeine (10mM) did not affect to $^{45}Ca-release.\;^{45}Ca-release$ was inhibited slightly ($3{\sim}8%\;by\;Mg^{2+}$) (5mM) or tetracaine (1mM), and moderately (23%) by high concentration of ruthenium red $(300\;{\mu}M)$. From the above results, it is suggested that SR Ca-release channel protein of crustacean has different properties from that of the rabbit, and similar properties between crayfish and lobster in functional and immunological aspects, but Ca-release via crayfish channel may be more sensitive to calcium.

• Food Science and Preservation
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• v.13 no.1
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• pp.13-17
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• 2006

The strawberry was dipped into $1\%\;CaCl_2$ solution at $20^{\circ}C\;and\;45^{\circ}C$ for 15min. respectively, and then packaged with or without PE film (thickness: 0.011mm) before putting into the cold storage at $5^{\circ}C$. The results showed the lowest rate of rot incidence and the highest firmness with higher Vitamin C content and the best superficial appearance in the treatment of $CaCl_2$ dipping at $45^{\circ}C$ with packaging. It also showed lower pH and higher titratable acidity in the treatment However, no significant difference of SSC was found among various treatments. The results suggested that the combination of postharvest calcium dipping and packaging could result in more effective preservation for strawberry compared with the individual treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.115-120
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• 1990

This study was conducted to investigate the relation of softening with the mineral compone-nts during ripening of tomato fruits. The mineral contents of Ca, K, Mg, Zn. Fe Mn and Cu and its existence form respiratory rate and hardness during ripening were evaluated. The respiratory rate of tomato fruits was decreased until 42 days after anthesis and then increased the climacteric maximum was found on 49 days after anthesis then decreased. The hardness of tomato fruits during ripening did not change greatly until 45days after anthesis then decrea-sed markedly. The major mineral components of tomato fruits were K, Ca, and Mg, Zn Fe Mn and Cu were the minor components. The contents of soluble Ca, Ma and K increased markedly and those of bound Ca and Mg decreased markedly after 45days during ripening,. However other components were not changed greatly.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.666-671
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• 1997

We studied effects of genistein and tyrphostin, inhibitors of tyrosine kinase, on contractions induced by high $K^+$ and norepinephrine in rat aorta. Genistein $(10^{-6}{\sim}10^{-4}M)$ and tyrphostin ($(10^{-5}{\sim}10^{-4}M)$) inhibited high $K^+$ and norepinephrine-induced sustained contractions, respectively in a concentration-dependent manner. High $K^+$ and norepinephrine caused an increase in $^{45}Ca^{2+}$ uptake while $10^{-4}M$ genistein and tyrphostin inhibited the $K^+$ and norepinephrine-increased $^{45}Ca^{2+}$ uptake, respectively. These results show that inhibitor of tyrosine kinase blocks the voltage-and receptor-operated $Ca^{2+}$ channels in rat aorta, respectively.

• Asian Journal of Turfgrass Science
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• v.13 no.4
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• pp.191-200
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• 1999

The objective of this study was to improve the recycling rate of coal ash fly, industrial waste. This study was conducted to analyze the physico-chemical properties of \"CellCaSi\" and clarify the effects on the growth of Kentucky bluegrass(Poa pratensis L.) and creeping bentgrass(Agrostis paulstris Huds \"Penncross\") and the chemical properties of soil, which was cellular calcium silicate reproduced by coal ash fly. A field assay was carried out in Young-Pyong Golf Course. The results were as follows. 1. The main chemical composition of CellCaSi was $SiO_2$(45~55%) and CaO(25~35), which was 70~90% of total weight. CellCaSi showed pH 8~9. Bulk density of CellCaSi was 0.35~0.45g/㎤. Water content of CellCaSi was 52.5~67.5%. 2. In the applied plots, leaf width, grass density per $1\textrm{cm}^2$, rhizome number and length per plant, and root number per plant of Kentucky bluegrass(Poa pratensis L.) and creeping bentgrass(Agrostis paulstris Huds \"Penncross\") showed increasing tendency compared with the control. The application of CellCaSi increased the growth of turfgrasses. Their visual quality on hardness, grass shoot density per $1\textrm{cm}^2$ and root growth was very good. And, their visual quality on rhizome growth was good. 3. After the application of CellCaSi, pH, CEC, Ex-cation of the applied soil showed increasing tendency with the little range, $SiO_2$content increasing tendency considerably, and organic matter content decreasing tendency compared with the control.ncy compared with the control.

• Proceedings of the Ginseng society Conference
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• 1980.09a
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• pp.71-76
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• 1980

Aortic strips were prepared from rabbits, and the tensions were maintained by administration of norepinephrine into the incubation chamber. The application of diol or triol induced relaxation of the aortic strip, as indicated by the decreased aortic tension. Triol, in a concentration of $30\;mg\%\;causes\;approximately\;50\%$ of muscle relaxation, whereas a similar degree of relaxation is induced by $50\;mg\%$ of diol. This indicates that both triol and diol cause relaxation of the aorta, but that triol is about $170\%$ more potent than diol. It is well established that blood-vessel smooth-muscle tone is regulated by the available intracellular $Ca^{++}$ concentration, which in turn is profoundly influenced by interaction of the cellular membrane and sarcoplasmic reticulum in the smooth muscle. Thus, any agent which modifies the smooth-muscle tone is expected to interfere with the $Ca^{++}$ binding or uptake of sarcolemma and sarcoplasmic reticulum. In the following experiments sarcoplasmic reticulum and sarcolemma were prepared from the ventricle of rabbit heart, and the active $Ca^{++}$ uptake by these cellular components was measured employing $Ca^{45}$ in the presence of triol and diol. It was found that the active $Ca^{++}$ uptake in the presence of ATP by sarcoplasmic reticulum was inhibited by both triol and diol. Panaxatriol, in a concentration of $80\;mg\;\%,$ inhibited $Ca^{++}$ uptake by $30\%,$ whereas panaxatriol in the same concentration inhibited uptake by $20\%.$ It is clear that triol is a more potent inhibitor of active $Ca^{++}$ transport in sarcoplasmic reticulum than diol. The $Ca^{++}$ binding of the cellular membrane was also studied employing Ca45 and milipore techniques. It was found that triol in a concentration of $80\;mg\;\%,$ decreased $Ca^{++}$ binding by $29\%.$ Diol in the same concentration decreased the binding by $17\%.$ It is clear that both triol and diol inhibit $Ca^{++}$ binding to the cellular membrane, but triol is approximately $180\%$ more potent than diol.

• Journal of Korean Dental Science
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• v.10 no.2
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• pp.45-52
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• 2017

Calcium has versatile roles in diverse physiological functions. Among these functions, intracellular $Ca^{2+}$ plays a key role during the secretion of salivary glands. In this review, we introduce the diverse cellular components involved in the saliva secretion and related dynamic intracellular $Ca^{2+}$ signals. Calcium acts as a critical second messenger for channel activation, protein translocation, and volume regulation, which are essential events for achieving the salivary secretion. In the secretory process, $Ca^{2+}$ activates $K^+$ and $Cl^-$ channels to transport water and electrolyte constituting whole saliva. We also focus on the $Ca^{2+}$ signals from intracellular stores with discussion about detailed molecular mechanism underlying the generation of characteristic $Ca^{2+}$ patterns. In particular, inositol triphosphate signal is a main trigger for inducing $Ca^{2+}$ signals required for the salivary gland functions. The biphasic response of inositol triphosphate receptor and $Ca^{2+}$ pumps generate a self-limiting pattern of $Ca^{2+}$ efflux, resulting in $Ca^{2+}$ oscillations. The regenerative $Ca^{2+}$ oscillations have been detected in salivary gland cells, but the exact mechanism and function of the signals need to be elucidated. In future, we expect that further investigations will be performed toward better understanding of the spatiotemporal role of $Ca^{2+}$ signals in regulating salivary secretion.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.5
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• pp.561-569
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• 2008

We analyzed contents of cations and anions for the domestic bottled drinking water. Results showed that total cation content was 45.81 mg/L and contained 40% of Ca. The content of cations were decreased in the order of Ca>Si>Na>Mg>K. Total anion content was 12.20 mg/L and contained 90% of ${SO_4}^{2-}$ and $Cl^-$. $F^-$ and $NO_{3-}N$ were a little contained. While Si content was reduced 2.3~75.7%(mean value:38.5%) after freezing, Ca content was reduced 45.2% after boiling. It showed that water containing higher Ca content was significantly decreased after boiling. Precipitates formed by freezing and boiling is composed of minerals such as Si and Ca. Compared to minerals from food intake, concentrations of minerals from water intake are expected to be less influenced. It is recommended Bottled Water that contains more than 20 mg/L of Ca(exceeding water-quality standard for turbidity) is safe to drink without thawing and boiling.