• Korean Journal of Food Science and Technology
• /
• v.29 no.5
• /
• pp.1071-1074
• /
• 1997

The Effect of $Ca^{++}$, $K^+$ and $Mg^{++}$ on salting of radish was investigated. Up to 0.2 M of $Ca^{++}$ and/or $K^+$, sodium chloride content of radish increased respectively, comparing with no addition of these ions. The salting effect of radish incereased in proportion to the concentration ($0{\sim}0.01\;M$) of $Ca^{++}$ and/or $K^+$ in the salting solution up to 0.2 M, while there was no influence of $Mg^{++}$. When $Mg^{++}$ and $Ca^{++}/Mg^{++}$ and $K^+$ were added to brine solution, $Ca^{++}$ or $K^+$ influenced the salting effect of radish and $Mg^{++}$ did not.

• The Korean Journal of Physiology
• /
• v.22 no.1
• /
• pp.13-29
• /
• 1988

In order to elucidate the regulatory mechanism of intracellular calcium ion concentrations, contractions or contractures induced by $Na^{+}-removal$, calcium-application or ouabain-treatment as an index of $Na^+/Ca^{2+}$ exchange activity were studied in atrial muscle or vascular smooth muscle (aorta and renal artery) of the rabbit. The magnitude of low sodium contractures in atrial trabeculae increased with sigmoid shape when external sodium concentrations were reduced to sodium-free condition, whereas that of calcium contracture intensified in a parabolic pattern when external calcium concentrations were elevated to 8 mM. $Na^{+}-removal$ contractures were induced in a duration-dependent manner to $K^{+}-free$ exposure and same findings were observed with ouabain treatment. $Na^{+}-free$ contractures were not affected by verapamil treatment, but stimulated by $100{\mu}M\;Mn^{2+}$ and inhibited by high concentrations of $Mn^{2+}\;(2{\sim}8mM)$ in a dose-dependent manner. Ryanodine which is known to suppress the release of calcium from internal store abolished spontaneous twitch contractions induced by $K^{+}-free$ solution, but had no effect on the development $Na^{+}-free$ contractures. Na-free contractures were not always induced in vascular smooth muscle preparations. Contractures by $O\;mM\;Na^+$ were usually seen in aorta, but not often in renal artery.$50\;mM\;K^+$, noradrenaline (NA) and angiotensin II (AII) always evoked very large contraction in all preparations of vascular smooth muscle. Contractures developed by $O\;mM\;Na^+$ were not sensitive to verapamil treatment as in atrial trabeculae, but were abolished by $100{\mu}M\;Mn^{2+}$. In contrast to $Na^{+}-free$ contractures, $Mn^{2+}(100{\mu}M)$ had no effect on the contractures induced by NA or 50 mM$K^+$. Caffeine in the concentration of 10 mM evoked transient contracture in the distal renal artery. The rate of spontaneous relaxation in caffeine contracture was dependent upon the concentrations of external sodium, and had double component of relaxation when the rate of relaxation was plotted in the semilogarithmic scale of relative tension versus time. Especially late components of relaxation had more direct relation to $Na^+$ concentrations. It could be concluded that $Na^+/Ca^{2+}$ exchange mechanism in the heart has a large capacity, inhibited by $Mn^{2+}$ but not by verapamil and ryanodine, while $Na^+/Ca^{2+}$ exchange system in vascular smooth muscle has a very low capacity especially in small artery, inhibited by low concentration of $Mn^{2+}\;(100{\mu}M)$ but not affected by verapamil and ryanodine.

• Korean Journal of Agricultural Science
• /
• v.42 no.4
• /
• pp.415-421
• /
• 2015

Ca is material to used in Chinese cabbage (Brasica rapa L. spp. pekinensis). The variation of inorganic ions and GSLs in Chinese cabbage cultivated to control additional Ca contents in slaked lime. The additional fertilizer of slaked lime differ four grade that 0 g (Ca-0), 0.28 g (Ca-1), 0.56 g (Ca-2), 0.84 g (Ca-3) are week intervals with a total of 8 times after transplanting. Inorganic ions in Chinese cabbage ('Bulam plus') were analyzed to use inductively coupled plasma atomic emission spectometry(ICP). The more additional slaked lime input, the more almost macronutrients contents were high except Ca. Ca contents were higher in Ca-0 (153.10) and lower in Ca-3 (130.55 mg/kg dry weight, DW). GSLs were identified based on peak retention time in previous results of our laboratory. Seven GSLs including two aliphatic (gluconapin, glucobrassicanapin), one aromatic (gluconasturtiin), four indolyl (glucobrassicin, neoglucobrassicin, 4-methoxyglucobrassicin, 4-hydroxyglucobrassicin) were detected using HPLC. Progoitrin, 4-methoxyglucobrassicin, and gluconasturtiin contents increased in proportion to the input in additional slaked lime. Total GSLs contents were Ca-0 (11.95), Ca-1 (17.02), Ca-2 (19.63), Ca-3 ($17.11{\mu}mol/g$ dry weight, DW). Total Ca and GSLs contents (Ca-1,2,3; mean 17.92) are higher than non treatment (Ca-0; $11.95{\mu}mol/g$ DW).

• The Korean Journal of Physiology
• /
• v.20 no.2
• /
• pp.199-208
• /
• 1986

The effects of $Mg^{++}$ upon the spontaneous contraction activated by 1 IU/l oxytocin were studied in the isolated rat uterine muscle. Longitudinal muscle strips u·ere prepared from the rat uteri at the estrous stage. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) In the uterine strips contracting spontaneously, as $Mg^{++}$ concentration increased in the Tyrode solution the amplitude of peak tension decreased in all the experimental solutions containing the various concentrations of $Ca^{++}\;(0.5{\sim}4 mM)$. And the amplitude of peak tension increased in inverse proportion to the $[Mg^{++}]/[Ca^{++}]\; ratio$. It is suggested that the tension-lowering effect of $Mg^{++}$ would be developed through decreasing intracellular ionized free calcium ion concentration by uncertain mechanism. 2) The frequency of the uterine contraction activated by oxytocin increased as the $[Mg^{++}]/[Ca^{++}]\;ratio$ ratio increased up to 1/2, but the frequency decreased above this ratio. It is speculated that $Mg^{++}$ would influence the excitability control action of $Ca^{++}$.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.1
• /
• pp.57-63
• /
• 2004

Fluoxetine, a widely used anti-depressant compound, has several additional effects, including blockade of voltage-gated ion channels. We examined whether fluoxetine affects ATP-induced calcium signaling in PC12 cells by using fura-2-based digital calcium imaging and assay for $[^3H]-inositol$ phosphates (IPs). Treatment with ATP $(100\;{\mu}M)$ for 2 min induced $[Ca^{2+}]_i$ increases. The ATP-induced $[Ca^{2+}]_i$ increases were significantly decreased by removal of extracellular $Ca^{2+}$ and treatment with the inhibitor of endoplasmic reticulum $Ca^{2+}$ ATPase thapsigargin $(1\;{\mu}M)$. Treatment with fluoxetine for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase concentration-dependently. Treatment with fluoxetine $(30\;{\mu}M)$ for 5 min blocked the ATP-induced $[Ca^{2+}]_i$ increase following removal of extracellular $Ca^{2+}$ and depletion of intracellular $Ca^{2+}$ stores. While treatment with the L-type $Ca^{2+}$ channel antagonist nimodipine for 10 min inhibited the ATP-induced $[Ca^{2+}]_i$ increases significantly, treatment with fluoxetine alone blocked the ATP-induced responses. Treatment with fluoxetine also inhibited the 50 mM $K^+-induced$ $[Ca^{2+}]_i$ increases completely. However, treatment with fluoxetine did not inhibit the ATP-induced $[^3H]-IPs$ formation. Collectively, we conclude that fluoxetine inhibits ATP-indueed $[Ca^{2+}]_i$ increases in PC12 cells by inhibiting both an influx of extracellular $Ca^{2+}$ and a release of $Ca^{2+}$ from intracellular stores without affecting IPs formation.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.3
• /
• pp.135-138
• /
• 2015

A manganese dioxide (MnO₂) layer and zinc (Zn) layer are used as the cathode and the anode to develop filmtype manganese battery, in which a stack of a MnO₂ layer, gel electrolyte, and Zn layer are sandwiched between two plastic layers. This paper describes the chemical equation of swelling control upon the film-type manganese battery. We examined the reduction of hydrogen formation, by using calcium hydroxide Ca(OH)₂ as an additive in the electrolyte of film-type manganese battery. The phenomena or an effect of reduced hydrogen gas was proven by cyclic voltammogram, X-ray photoelectron spectra (XPS), and volume of hydrogen formation. The amount of H₂ gas generation in the presence of Ca²⁺ ion was reduced from 4.81 to 4.15 cc/g-zinc (14%), and the corrosion of zinc electrode in the electrolyte was strongly inhibited as time passed.

• Computers and Concrete
• /
• v.23 no.5
• /
• pp.351-359
• /
• 2019

In this study, the calcium hydroxide, an inherent product of cement hydration, was treated using biomimetic carbonation method of incorporating stearic acid to generate the hydrophobic calcium carbonate on concrete surface. Carbonation reaction was carried out at various $CO_2$ pressure and temperatures and utilizing the Scanning Electron Microscope (SEM), chloride-ion penetration test apparatus, and compression test machine to investigate the hydrophobicity, durability, and mechanical properties of the synthesized products. Experimental results indicate that the calcium stearate may change the surface property of concrete from hydrophilicity to hydrophobicity. Increasing reaction temperature can change the particles from irregular shapes to needle-rod structures with increased shear stress and thus favorable to hydrophobicity and microhardness. The contact angle against water for the concrete surface was found to increase with increasing $CO_2$ pressure and temperature, and reached to an optimum value at around $90^{\circ}C$. The maximum static water contact angle of 128.7 degree was obtained at the $CO_2$ pressure of 2 atm and temperature of $90^{\circ}C$. It was also found that biomimetic carbonation increased the permeability, acid resistance and chloride-ion permeability of the concrete material. These unique results demonstrate that the needle-rod structures of $CaCO_3$ synthetized on concrete surface could enhance hydrophobicity, durability, and mechanical properties of concrete.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.6
• /
• pp.835-840
• /
• 2006

Dimethyl 1-(4-nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate has been used as an ionophore and o-nitrophenyloctyl ether as a plasticizer in order to develop a poly(vinyl chloride)-based membrane electrode for calcium ion detection. The sensors exhibit significantly enhanced response towards calcium(II) ions over the concentration range $8.0{\times}10^{-7}\;1.0{\times}10^{-1}$ M at pH 3.0-11 with a lower detection limit of $5.0 {\times}10^{-7}$ M. The sensors display Nernstian slope of 29.5 ${\pm}$ 0.5 mV per decade for Ca(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. It has a fast response time within 10 s over the entire concentration range and can be used for at least 2 months without any divergence in potentials. The proposed electrode revealed good selectivity and response for $Ca^{2+}$ over a wide variety of other metal ions. The selectivity of the sensor is comparable with those reported for other such electrodes. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Ca(II) solution, with EDTA.

• Journal of Environmental Science International
• /
• v.24 no.5
• /
• pp.615-622
• /
• 2015

East Asia is characterized by anthropogenic emissions resulting from the large population and fast economic growth of this region. Since the prevailing wind is westerly and northwesterly, emissions from Ul-jin can be expected to contribute to acidic deposition increase in downwind direction. Aerosols collected at the near coast site, Uljin geun, gyungbook and were analyzed for $NH_4{^+}$, $Mg^{2+}$, $Na^+$, $Ca^{2+}$, $Cl^-$, $SO_4{^{2-}}$, and $NO_3{^-}$ from Aug. 2012 to Feb. 2013. The seasonal averaged aerosol concentration showed the highest potassium and calcium ion in winter and the highest ammonium ion due to a meadow and high solar intensity in summer. Sodium and chloride ion showed the same ratio all seasons and sulfate and nitrate species showed the maximum value in winter Chemical components of aerosols collected at the near coast site, Uljin geun, gyungbook were lower by 16 to 73% than those collected at other similar environment site such as kanghwa, yangyang. Comparing air quality data at the near coast site, Uljin geun, gyungbook, There was found that Uljin coast site is less influenced by the sea salts(potassium, magnesium, calcium) and nss-$SO_4{^{2-}}$ percentage is 3~13% higher than similar condition site.

• Journal of Korean Society of Water and Wastewater
• /
• v.33 no.2
• /
• pp.95-101
• /
• 2019

High voltage impulse(HVI) has been gained attention as an alternate technique controlling $CaCO_3$ scale formation. Investigation of key operational parameters for HVI is important, however, those had not been reported yet. In this study, the effect of temperature and applied voltage of HVI on $Ca^{2+}$ concentration was studied. As the applied voltage from 0 to 15kV and the temperature increased from 20 to $60^{\circ}C$, the $Ca^{2+}$ concentration decreased, indicating that the aqueous $Ca^{2+}$ precipitated to $CaCO_3$. The $Ca^{2+}$ concentration decreased up to 81% under the condition of 15kV and $60^{\circ}C$. Rate constant for the precipitation reaction, k was determined under different temper1ature and voltage. The reaction rate constant under the 15kV and $60^{\circ}C$ condition was evaluated to $66{\times}10^{-3}L/(mmol{\cdot}hr)$, which was 5 times greater than the k of the reaction without HVI at same temperature. The increases in k by HVI at higher temperature region(40 to $60^{\circ}C$) was much greater than at lower temperature region(20 to $40^{\circ}C$), which implies temperature is more important parameter than voltage for reducing $Ca^{2+}$ concentration at high temperature region. These results show that the HVI induction accelerates the precipitation to $CaCO_3$, particularly much faster at higher temperature.