Journal articles: 'Calcium ions'

1

McDonough, Paul G., and Chuang-Ye Hong. "Calcium Ions and Sperm." Fertility and Sterility 56, no. 1 (July 1991): 153. http://dx.doi.org/10.1016/s0015-0282(16)54440-9.

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Cheng, Gege, Wenwen Li, Long Li, Fuhou Lei, Xiuyu Liu, and Qin Huang. "Removing Calcium Ions from Remelt Syrup with Rosin-Based Macroporous Cationic Resin." Polymers 14, no. 12 (June 14, 2022): 2397. http://dx.doi.org/10.3390/polym14122397.

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Mineral ions (mainly calcium ions) from sugarcane juice can be trapped inside the heating tubes of evaporators and vacuum boiling pans, and calcium ions are precipitated. Consequently, sugar productivity and yield are negatively affected. Calcium ions can be removed from sugarcane juice using adsorption. This paper described the experimental condition for the batch adsorption performance of rosin-based macroporous cationic resins (RMCRs) for calcium ions. The kinetics of adsorption was defined by the pseudo-first-order model, and the isotherms of calcium ions followed the Freundlich isotherm model. The maximal monolayer adsorption capacity of calcium ions was 37.05 mg·g−1 at a resin dosage of 4 g·L−1, pH of 7.0, temperature of 75 °C, and contact time of 10 h. It appeared that the adsorption was spontaneous and endothermic based on the thermodynamic parameters. The removal rate of calcium ions in remelt syrup by RMCRs was 90.71%. Calcium ions were effectively removed from loaded RMCRs by 0.1 mol·L−1 of HCl, and the RMCRs could be recycled. The dynamic saturated adsorption capacity of RMCRs for calcium ions in remelt syrup was 37.90 mg·g−1. These results suggest that RMCRs are inexpensive and efficient adsorbents and have potential applications for removing calcium ions in remelt syrup.

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Tsukui, Kei, Takuya Kakiuchi, Hidetomo Sakurai, and Yoshihiro Tokudome. "Shotokuseki Extract Promotes Keratinocyte Differentiation Even at a Low Calcium Concentration." Applied Sciences 12, no. 5 (February 22, 2022): 2270. http://dx.doi.org/10.3390/app12052270.

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The switch between keratinocyte proliferation and differentiation is regulated by extracellular calcium levels, requiring high concentrations (>1 mol/L) of extracellular calcium to induce differentiation. The Shotokuseki extract (SE) contains various ions such as calcium, but its effect on keratinocytes is unknown. This study focused on calcium-induced differentiation of keratinocytes and investigated the effects of simultaneous application of calcium and other ions on keratinocyte differentiation. The expression of differentiation markers increased when SE was added to a keratinocyte culture but not when only calcium was added at the same concentration present in SE. The calcium concentration in SE was found to be too low (0.01 mol/L) to induce differentiation of keratinocytes. In addition, the application of SE increased intracellular calcium concentration compared with calcium solution alone. Therefore, the induction of keratinocyte differentiation by SE is not calcium-dependent, or SE may alter the calcium sensitivity of keratinocytes. In our study, we found that simultaneous application of multiple ions and/or the application of trace ions may alter calcium sensitivity and the epidermal cell response. The function of ion transporters associated with these ions and the response of cells to ions depends largely on the balance among various ions and the function of trace ions.

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Meng, Yue Cheng, Lun Bo Hong, and Jian Qiu Jin. "A Study on the Gelation Properties and Rheological Behavior of Gellan Gum." Applied Mechanics and Materials 284-287 (January 2013): 20–24. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.20.

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The effects of gellan gum and calcium ions concentration on gelation characteristics and rheological behavior were investigated using TA(texture analysis)and mechanical rheometer which monitored respectively press strength and the evolution of G′. At a premium gellan gum content of 0.02g in 100ml buffer solution, increasing calcium ions concentration led to an increase in the gelation strength, but when calcium ions content reached a critical concentration values range from 0.015% to 0.02%, gelation strength begin to decrease. While in the same content of calcium ions, calcium lactate exhibits grater effects on gelation strength than calcium chloride. The temperature at the onset of gelation and the gelation rates showed an increase with the increasing of gellen and calcium ions content. At the same calcium ions concentration, the evolution of modulus storage (G′), gel temperature and rate are higher with the addition of calcium lactate than using calcium chloride. Our study indicated exponential relationship between gelling temperature (gelling rate) and calcium concentration.

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5

GORDIENKO, Katerina, Yaroslav RADOVENCHYK, Tamara KRYSENKO, and Vyacheslav RADOVENCHYK. "EFFICIENCY OF PLANTING CALCIUM IONS FROM DILUTE AQUEOUS SOLUTIONS IN THE FORM OF PHOSPHATES." Herald of Khmelnytskyi National University. Technical sciences 313, no. 5 (October 27, 2022): 134–40. http://dx.doi.org/10.31891/2307-5732-2022-313-5-134-140.

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The specifics of calcium phosphate formation process during diluted aqueous solutions softening for home or office were researched. Studies have shown that, unlike calcium carbonate, effective precipitation of calcium ions with phosphate is possible even at doses less than stoichiometric. The ratio between concentrations of phosphate ions and calcium ions K = [PO43-, mg-eq] / [Ca2+, mg-eq] is a determining factor. Already at K = 0.5 there is a decrease in the content of calcium ions by more than half. In stoichiometry (K = 1), the residual concentrations of calcium ions in the treated water fall below 1 mg-eq/dm3. At K > 1.5, the content of calcium ions in the treated water stabilizes at the level of 0.2 – 0.1 mg-eq/dm3. Water temperature does not significantly affect the deposition of calcium ions with phosphates. A noticeable decrease in efficiency is recorded only at a temperature of 5 ° C. But even in this case, this decrease is 0.1 – 1.5 mg-eq/dm3, which is quite acceptable for living conditions, since it provides soft and very soft water. The reaction between calcium ions and phosphates is quite complete in the first minutes of contact. The settling of mixed solutions for an hour showed that the reaction of the formation of a solid phase takes place at the time of draining the solutions and over time the residual hardness of the water practically does not change. From the point of view of softening efficiency, phosphate is quite suitable as a reagent for removing calcium ions from hard natural waters. An important aspect of the softening technology is the separation of the precipitate formed from the treated water. To do this, it is necessary to determine the conditions for the formation of a crystalline, most compact and formed precipitate. The clarification of the hard water sample treated with sodium phosphate showed that there was no significant difference in deposition at different initial pH values.

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6

Deftereos, Spyridon, Nikolaos Papoutsidakis, Georgios Giannopoulos, Christos Angelidis, Konstantinos Raisakis, Georgios Bouras, Periklis Davlouros, et al. "Calcium Ions in Inherited Cardiomyopathies." Medicinal Chemistry 11, no. 999 (September 28, 2015): 1. http://dx.doi.org/10.2174/1573406411666150928113018.

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7

Deftereos, Spyridon, Nikolaos Papoutsidakis, Georgios Giannopoulos, Christos Angelidis, Konstantinos Raisakis, Georgios Bouras, Periklis Davlouros, et al. "Calcium Ions in Inherited Cardiomyopathies." Medicinal Chemistry 12, no. 2 (February 8, 2016): 139–50. http://dx.doi.org/10.2174/157340641202160209093713.

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8

Kostiuk, PH. "Calcium ions in cell nucleus." Fiziolohichnyĭ zhurnal 56, no. 4 (July 15, 2010): 10–13. http://dx.doi.org/10.15407/fz56.04.010.

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9

Brown, Edward M., Peter M. Vassilev, and Steven C. Hebert. "Calcium ions as extracellular messengers." Cell 83, no. 5 (December 1995): 679–82. http://dx.doi.org/10.1016/0092-8674(95)90180-9.

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10

Nakai, Junichi, and Masamichi Ohkura. "Probing Calcium Ions with Biosensors." Biotechnology and Genetic Engineering Reviews 20, no. 1 (December 2003): 3–22. http://dx.doi.org/10.1080/02648725.2003.10648035.

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11

Wojda, Urszula, Elzbieta Salinska, and Jacek Kuznicki. "Calcium ions in neuronal degeneration." IUBMB Life 60, no. 9 (September 2008): 575–90. http://dx.doi.org/10.1002/iub.91.

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12

Goblet, C., and Y. Mounier. "Activation of skinned muscle fibers by calcium and strontium ions." Canadian Journal of Physiology and Pharmacology 65, no. 4 (April 1, 1987): 642–47. http://dx.doi.org/10.1139/y87-107.

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Intact and mechanically skinned skeletal muscle fibers of the crab Carcinus maenas have been used. The aim of the experiments was to determine the origin of the mechanical activity recorded in intact crab muscle fibers exhibiting an inward strontium current in strontium solution without calcium. To do so, the effect of strontium ions in inducing activation of contractile proteins and calcium release from the sarcoplasmic reticulum has been studied. The properties of the sarcoplasmic reticulum membrane towards strontium ions, i.e., the efficiency of the calcium ATPase towards strontium ions and the capability to release strontium ions have been investigated. Results show that the contractile proteins have a lower affinity for strontium than for calcium ions. However, the maximum bound strontium is identical to the maximum bound calcium. As for the sarcoplasmic reticulum, strontium ions can induce a calcium release and also can be taken up by the calcium ATPase and be released. We concluded that the mechanical activity in intact fibers bathed in a strontium medium has two origins: first, a direct and partial activation of the contractile proteins by strontium ions flowing through the calcium channel; second, a contractile proteins activation of calcium ions released by the sarcoplasmic reticulum by a "strontium-induced calcium release" mechanism.

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13

Jamalian, Azadeh, Evert-Jan Sneekes, Lennard J. M. Dekker, Mario Ursem, Theo M. Luider, and Peter C. Burgers. "Dimerization of Peptides by Calcium Ions: Investigation of a Calcium-Binding Motif." International Journal of Proteomics 2014 (September 14, 2014): 1–8. http://dx.doi.org/10.1155/2014/153712.

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We investigated calcium-binding motifs of peptides and their recognition of active functionalities for coordination. This investigation generates the fundamentals to design carrier material for calcium-bound peptide-peptide interactions. Interactions of different peptides with active calcium domains were investigated. Evaluation of selectivity was performed by electrospray ionization mass spectrometry by infusing solutions containing two different peptides (P1 and P2) in the presence of calcium ions. In addition to signals for monomer species, intense dimer signals are observed for the heterodimer ions (P1⋯Ca2+⋯P2) (⋯ represents the noncovalent binding of calcium with the peptide) in the positive ion mode and for ions (P1-2H2-⋯Ca2+⋯P2-2H2-) in the negative ion mode. Monitoring of the dissociation from these mass selected dimer ions via the kinetic method provides information on the calcium affinity order of different peptide sequences.

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14

Walden, J., H. Straub, and E. J. Speckmann. "Epileptogenesis: Contributions of calcium ions and antiepileptic calcium antagonists." Acta Neurologica Scandinavica 86, S140 (November 1992): 41–46. http://dx.doi.org/10.1111/j.1600-0404.1992.tb04469.x.

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15

Veklich, T. O., Yu V. Nikonishyna, and S. O. Kosterin. "Pathways and mechanisms of transmembrane calcium ions exchange in the cell nucleus." Ukrainian Biochemical Journal 90, no. 4 (June 22, 2018): 5–24. http://dx.doi.org/10.15407/ubj90.04.005.

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16

Huang, Yan C., Frederick M. Fowkes, Thomas B. Lloyd, and Nigel D. Sanders. "Adsorption of calcium ions from calcium chloride solutions onto calcium carbonate particles." Langmuir 7, no. 8 (August 1991): 1742–48. http://dx.doi.org/10.1021/la00056a028.

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17

Toffaletti, J., and B. Abrams. "Effects of in vivo and in vitro production of lactic acid on ionized, protein-bound, and complex-bound calcium in blood." Clinical Chemistry 35, no. 6 (June 1, 1989): 935–38. http://dx.doi.org/10.1093/clinchem/35.6.935.

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Abstract We have studied, both in vitro and in vivo, the quantitative effects of lactic acid production on concentrations of ionized calcium, bound calcium, pH, bicarbonate, and albumin. To do so, we examined the effects of addition of aqueous solutions of either hydrochloric acid, lactic acid, or lithium lactate to blood; we studied in vitro accumulation by storing blood sealed in tubes at room temperature for 5 h, then exposing the blood to air; and we induced in vivo production of lactic acid in healthy individuals who climbed stairs for 10 min. Lactic acid evidently affects the ionized, protein-bound, and complex-bound calcium concentrations in the following ways: (a) hydrogen ions from lactic acid bind to protein, which decreases protein-bound calcium; (b) lactate chelates calcium ions from free ionized calcium and protein-bound calcium about equally; and (c) the loss of a millimole of bicarbonate, either by exposure of blood to air or by respiratory alkalosis, results in the release of about 7 mumol of calcium ions, which re-equilibrate with both the protein-bound and ionized calcium. Because lactate apparently removes calcium ions directly from albumin, our study indicates that protein-bound calcium readily provides calcium ions that buffer changes in the concentration of ionized calcium.

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18

Mai, Qiongyin, Hanyu Zhou, and Leming Ou. "Flotation Separation of Chalcopyrite and Talc Using Calcium Ions and Calcium Lignosulfonate as a Combined Depressant." Metals 11, no. 4 (April 16, 2021): 651. http://dx.doi.org/10.3390/met11040651.

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As a major gangue mineral in sulfide ores, talc is difficult to separate from chalcopyrite in the flotation process due to its natural floatability, which affects the subsequent smelting process. In this study, the effects of calcium ions and calcium lignosulfonate (CLS) as a combination depressant for talc were systematically investigated along with the fundamental mechanisms. The results of our flotation tests showed the talc floating can be effectively depressed via the combination depressant effect of calcium ions and CLS over the pH range of 6–12. Measurements of the adsorption capacity, zeta potential, and Fourier transform infrared (FTIR) showed an enhancement of the adsorption capacity and adsorption strength of CLS on the talc surface after calcium ions were added. This result indicates that calcium ions adsorbed onto the talc, neutralized the negative charge on the surface of talc, generated the binding site with CLS, and formed the [talc-Ca2+/Ca(OH)+-CLS] system by strong adsorption. Further, the coverage rate of CLS on talc was significantly improved after the addition of calcium ions, as shown in the AFM imaging.

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19

Hsu, Yu-Chao, Li-Cheng Pan, and Lie-Ding Shiau. "A Photomicroscopic Study on the Growth Rates of Calcium Oxalate Crystals in a New Synthetic Urine without Inhibitors and with Various Inhibitors." Crystals 11, no. 3 (February 25, 2021): 223. http://dx.doi.org/10.3390/cryst11030223.

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A photomicroscopic growth apparatus was used to study the growth rates of calcium oxalate crystals in a new synthetic urine without inhibitors and with various inhibitors, including magnesium ions, citrate ions, chondroitin sulfate ions, and phytate ions. The dependence of growth rates on supersaturation at different temperatures without inhibitors was investigated using a power law model in terms of the Arrhenius form. The effects of various inhibitors on the growth rates of calcium oxalate indicated that the inhibition of growth rates increases in the order magnesium ions < citrate ions < chondroitin sulfate ions < phytate ions. The polymorphic forms of calcium oxalate crystals without inhibitors and with various inhibitors were examined by scanning electron microscopy.

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20

NIELSEN, Anders D., Claus C. FUGLSANG, and Peter WESTH. "Effect of calcium ions on the irreversible denaturation of a recombinant Bacillus halmapalus alpha-amylase: a calorimetric investigation." Biochemical Journal 373, no. 2 (July 15, 2003): 337–43. http://dx.doi.org/10.1042/bj20030220.

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The effect of temperature and calcium ions on the denaturation of a recombinant α-amylase from Bacillus halmapalus α-amylase (BHA) has been studied using calorimetry. It was found that thermal inactivation of BHA is irreversible and that calcium ions have a significant effect on stability. Thus an apparent denaturation temperature (Td) of 83 °C in the presence of excess calcium ions was observed, whereas Td decreased to 48 °C when calcium was removed. The difference in thermal stability with and without calcium ions has been used to develop an isothermal titration calorimetric (ITC) procedure that allows simultaneous determination of kinetic parameters and enthalpy changes of the denaturation of calcium-depleted BHA. An activation energy EA of 101 kJ/mol was found for the denaturation of calcium-depleted BHA. The results support a kinetic denaturation mechanism where the calcium-depleted amylase denatures irreversibly at low temperature and if calcium ions are in excess, the amylase denatures irreversibly at high temperatures. The two denaturation reactions are coupled with the calcium-binding equilibrium between calcium-bound and -depleted amylase. A combination of the kinetic denaturation results and calcium-binding constants, determined by isothermal titration calorimetry, has been used to estimate kinetic stability, expressed in terms of the half-life of BHA as a function of temperature and free-calcium-ion concentration. Thus it is estimated that the apparent EA can be increased to approx. 123 kJ/mol by increasing the free-calcium concentration.

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21

Allouch, Amena, Lyn Jaber, and Rim Nasser. "Regulated Natural Solution Containing Calcium Ions." International Journal of Scientific and Research Publications (IJSRP) 9, no. 1 (January 24, 2019): p8588. http://dx.doi.org/10.29322/ijsrp.9.01.2019.p8588.

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22

Ischenko, V., А. Ohmakevich, M. Ischenko, and T. Panchuk. "Determination of calcium ions in wine." Scientific Works of National University of Food Technologies 26, no. 5 (October 2020): 95–101. http://dx.doi.org/10.24263/2225-2924-2020-26-5-13.

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23

Xu, Zhaolong, Dayong Zhang, Xiaolan He, Yihong Huang, and Hongbo Shao. "Transport of Calcium Ions into Mitochondria." Current Genomics 17, no. 3 (March 29, 2016): 215–19. http://dx.doi.org/10.2174/1389202917666160202215748.

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24

Rutecki, Paul. "Calcium Ions in Nerve Cell Function." Journal of Clinical Neurophysiology 10, no. 2 (April 1993): 253. http://dx.doi.org/10.1097/00004691-199304000-00038.

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25

Váró, György, Leonid S. Brown, Richard Needleman, and Janos K. Lanyi. "Binding of Calcium Ions to Bacteriorhodopsin." Biophysical Journal 76, no. 6 (June 1999): 3219–26. http://dx.doi.org/10.1016/s0006-3495(99)77473-4.

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26

Oshima, Genichiro. "Inhibition by calcium ions of thrombin." Thrombosis Research 58, no. 4 (May 1990): 383–93. http://dx.doi.org/10.1016/0049-3848(90)90209-u.

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27

Iida, Shozo. "Interaction of calcium ions and polyelectrolytes." Biophysical Chemistry 57, no. 2-3 (January 1996): 133–42. http://dx.doi.org/10.1016/0301-4622(95)00068-8.

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28

Komínková, Viera, Marta Novotová, Karol Ondriaš, Tatiana Ravingerová, and Adam Szewczyk. "Mitochondrial Channels Permeable by Calcium Ions." Toxicology Mechanisms and Methods 14, no. 1-2 (January 2004): 35–39. http://dx.doi.org/10.1080/15376520490257428.

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29

Orrenius, Sten, Mark J. Burkitt, George E. N. Kass, Jeannette M. Dypbukt, and Pierluigi Nicotera. "Calcium ions and oxidative cell injury." Annals of Neurology 32, S1 (1992): S33—S42. http://dx.doi.org/10.1002/ana.410320708.

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30

Riccardi, D. "Calcium ions as extracellular, first messengers." Zeitschrift f�r Kardiologie 89, no. 14 (February 1, 2000): S009—S014. http://dx.doi.org/10.1007/s003920070094.

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31

Brown, D. A. "Calcium ions in nerve cell function." FEBS Letters 316, no. 2 (January 25, 1993): 199–200. http://dx.doi.org/10.1016/0014-5793(93)81219-p.

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32

Carolyn Wilke, special to C&EN. "Tracking calcium ions in sensitive plants." C&EN Global Enterprise 100, no. 43 (December 5, 2022): 9. http://dx.doi.org/10.1021/cen-10043-scicon2.

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33

Kabis, Charles W., Martha M. Sarasua, Karen E. Gottschalk, Carolyn D. Bourne, Lee G. Pedersen, Craig M. Jackson, Richard G. Hiskey, and Karl A. Koehler. "A Kinetic Model Describing the Interaction of Bovine Prothrombin Fragment 1 with Calcium Ions." Thrombosis and Haemostasis 53, no. 01 (1985): 019–23. http://dx.doi.org/10.1055/s-0038-1661228.

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SummaryA kinetic model is derived for the interaction of bovine prothrombin fragment 1 with calcium ions. The model requires binding of a minimum of two calcium ions for induction of the observed biphasic fluorescence decrease as a function of time. The model is shown to be consistent with experimental kinetic and equilibrium data by fitting theoretical curves for the biphasic fluorescence change to the data through exact solution of the nonlinear differential rate equations derived from the model. The rate constants for the binding of these two required calcium ions are calculated from the solutions as best fit parameters. The thermodynamic equilibrium constants, K1 and K2, for the binding of these two calcium ions are calculated from ratios of the forward and reverse rate constants as 0.6 × 104 and 5.4 × 104, respectively. Thus, the model correctly predicts positively cooperative calcium ion binding for at least the two calcium ions required to induce fluorescence quenching.

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34

Braudo, E. E., A. A. Soshinsky, V. P. Yuryev, and V. B. Tolstoguzov. "The interaction of polyuronides with calcium ions. 1: binding isotherms of calcium ions with pectic substances." Carbohydrate Polymers 18, no. 3 (January 1992): 165–69. http://dx.doi.org/10.1016/0144-8617(92)90060-4.

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35

Nuriddinova, Dilfuza. "Adsorption Equilibrium, Kinetics, Thermodynamics and Dynamic Separation of Magnesium and CalciumIons from Industrial Wastewater by New Strong Acid Cation Resin of SPVC." Pakistan Journal of Analytical & Environmental Chemistry 22, no. 1 (June 23, 2021): 127–38. http://dx.doi.org/10.21743/pjaec/2021.06.13.

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In the research work, the adsorption equilibrium, kinetics, thermodynamics and dynamic separation of magnesium and calcium ions from industrial wastewater by new strong acid cation resin of SPVC (sulphonated polyvinylchloride) were investigated. The sorption capacity of the studied resin was 3.78 mmol/g and 3.74 mmol/g for magnesium and calcium ions, respectively, according to Langmuir isotherm. It was found that the pseudo−first−order model was better fitted for the adsorption kinetics of magnesium and calcium ions on the resin. The dynamic separation results confirmed that the selected resin effectively separated magnesium and calcium ions from industrial wastewater in the dynamic condition. The change of the standard Gibbs free energy (G) and enthalpy (H), and entropy (S) were calculated. The obtained results confirmed that the adsorption of magnesium and calcium ions on the selected resin is endothermic.

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Ren, Hao, Jing Ning, and Gui Lan Song. "Study on the Interaction in Silica-Sphalerite-Mixture (Silica:Sphalerite =4:1)-Calcium Carbonate Systems." Advanced Materials Research 524-527 (May 2012): 1105–8. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.1105.

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There is a remarkable interaction when fine particles adsorbed calcium ions in sphalerite / silica system, it is not conducive to mineral flotation. The key is to how to reduce or eliminate calcium ions. The calcium ions concentration is decreased significantly if the accumulation of gypsum is converted to calcium carbonate in the circulating water. This paper focuses on Zeta potential and Zeta potential distribution (ZPD) with single minerals and Mixture (silica/sphalerite=4:1) in calcium carbonate solution, and the interactions of the sphalerite / silica particles was analyzed.

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37

Nur Faiqa, Mohamed Niza, and A. Nurazreena. "Effect of Hydrothermal Treatment in Calcium Phosphate Solution on SUS304 Substrate." Solid State Phenomena 264 (September 2017): 232–35. http://dx.doi.org/10.4028/www.scientific.net/ssp.264.232.

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SUS 304 stainless steel is known to be a biocompatible material and is widely used as screws or plates. However, issues regarding iron ion release after implantation become a concern which limits the application of SUS304. Therefore, to overcome these shortcomings, surface modification on SUS304 by forming calcium layer is needed to disable iron release from the substrate and also to encourage cell attachment. In this study, initially SUS 304 substrate are subjected to electrolysis process in sodium chloride solution to form pitting corrosion. These pitting corrosion will give the anchoring effect for the calcium ions to attach. Then the substrate are subjected to hydrothermal treatment at 200°C in calcium phosphate solution for 24, 36, 48, and 60 hours for deposition of calcium ions on the pitted SUS304 surface. Surface morphology observed by scanning electron microscope (SEM) shows that the calcium ions were deposited on the surface of the SUS304 substrate regardless hydrothermal treatment time. Rockwell hardness values shows that as hydrothermal treatment time increased the hardness value decreases. Therefore, hydrothermal treatment method enables the deposition of calcium ions layer on the surface of SUS304 which will inhibit the release of iron ions and enhanced bone attachment with the implant due to the bonding of the calcium ions with the bone.

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38

Chovancova, Barbora, Veronika Liskova, Petr Babula, and Olga Krizanova. "Role of Sodium/Calcium Exchangers in Tumors." Biomolecules 10, no. 9 (August 31, 2020): 1257. http://dx.doi.org/10.3390/biom10091257.

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The sodium/calcium exchanger (NCX) is a unique calcium transport system, generally transporting calcium ions out of the cell in exchange for sodium ions. Nevertheless, under special conditions this transporter can also work in a reverse mode, in which direction of the ion transport is inverted—calcium ions are transported inside the cell and sodium ions are transported out of the cell. To date, three isoforms of the NCX have been identified and characterized in humans. Majority of information about the NCX function comes from isoform 1 (NCX1). Although knowledge about NCX function has evolved rapidly in recent years, little is known about these transport systems in cancer cells. This review aims to summarize current knowledge about NCX functions in individual types of cancer cells.

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39

Yang, Ting, Zhiru Hu, Jilin Liu, Zhiquan Zhang, and Guodong Feng. "A novel phosphonic acid functional polythiophene fluorescent sensor for Ca2+ and its live cell imaging." Analytical Methods 11, no. 39 (2019): 4991–97. http://dx.doi.org/10.1039/c9ay01318k.

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40

Graber, Z. T., W. Wang, G. Singh, I. Kuzmenko, D. Vaknin, and E. E. Kooijman. "Competitive cation binding to phosphatidylinositol-4,5-bisphosphate domains revealed by X-ray fluorescence." RSC Advances 5, no. 129 (2015): 106536–42. http://dx.doi.org/10.1039/c5ra19023a.

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Calcium ions bind strongly to PIP₂ at physiological concentrations, leading to condensation and decreased effective charge for PIP₂. Calcium displaces the more numerous magnesium and potassium ions, but some potassium ions remain.

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41

Owczarz, Piotr, Anna Rył, Marek Dziubiński, and Jan Sielski. "Injectable Chitosan Scaffolds with Calcium β-Glycerophosphate as the Only Neutralizing Agent." Processes 7, no. 5 (May 19, 2019): 297. http://dx.doi.org/10.3390/pr7050297.

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The presented work describes the method of preparation of thermosensitive chitosan hydrogels using calcium β-glycerophosphate salt as the only pH neutralizing agent and supporting the crosslinking process. The presence of calcium ions instead of sodium ions is particularly important in the case of scaffolds in bone tissue engineering. Rheological and physicochemical properties of low concentrated chitosan solutions with the addition of calcium β-glycerophosphate were investigated using rotational rheometry techniques, Zeta potential (by electrophoresis), XPS, and SEM analysis together with an EDS detector. It was found to be possible to prepare colloidal solutions of chitosan containing only calcium β-glycerophosphate (without sodium ions) undergoing a sol-gel phase transition at the physiological temperature of the human body. It has also been shown that it is possible to further enrich the obtained cellular scaffolds with calcium ions. Using the addition of calcium carbonate, hydrogels with a physiological ratio of calcium to phosphorus (1.6–1.8):1 were obtained.

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Higuchi, S., A. Takeshita, H. Higashi, N. Ito, T. Imaizumi, H. Matsuguchi, and M. Nakamura. "Lowering calcium in the nucleus tractus solitarius causes hypotension and bradycardia." American Journal of Physiology-Heart and Circulatory Physiology 250, no. 2 (February 1, 1986): H226—H230. http://dx.doi.org/10.1152/ajpheart.1986.250.2.h226.

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It has been shown that saline microinjected into the region of the nucleus tractus solitarius (NTS) causes, but artificial cerebrospinal fluid (CSF) in the same volume does not cause, hypotension and bradycardia. This study was done to examine the possibility that the difference in effects between saline and artificial CSF may be due to the lack of calcium ions in saline. In anesthetized rats, saline or artificial CSF with or without calcium ions was microinjected into the region of the NTS. Saline microinjected in volumes of 0.2 and 0.5 microliter produced the volume-dependent decreases in arterial pressure and heart rate. Saline with added calcium ions and artificial CSF did not elicit the hypotensive and bradycardic response, but artificial CSF without calcium ions produced hypotension and bradycardia. These results suggest that the lack of calcium ions in the injected solutions is the factor that determines the hypotensive and bradycardic response. These results suggest that lowering the local availability of calcium to the NTS neurons results in hypotension and bradycardia.

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Alsaiari, H. A. A., A. Kan, and M. B. B. Tomson. "Effect of Calcium and Iron (II) Ions on the Precipitation of Calcium Carbonate and Ferrous Carbonate." SPE Journal 15, no. 02 (March 11, 2010): 294–300. http://dx.doi.org/10.2118/121553-pa.

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Summary This work was intended to study the interaction between ferrous-iron and calcium ions simultaneously toward carbonate ions in supersaturated solution in a continuous stirred tank reactor (CSTR) and to establish an acceptable experimental design as a preparation step to study the kinetics of other types of ferrous iron salts. The experiments were conducted in 0.5 M NaCl solution at 55°C. The pH values were between 6.2 and 7.8. It was found that calcium ions have a strong influence in increasing the solubility of iron carbonate. On the other hand, ferrous iron did not affect the solubility of calcium carbonate significantly. This might be caused by increasing the stability of ferrous iron carbonate complexes in the presence of calcium. Also, the molar ratios of calcium to iron in the solution were compared with their molar ratios in the precipitated salts. It was found that the relation was greater than unity; Rsolid/Rsolution = 2.39. Thus, calcium carbonate has a preference to precipitate. This result seems to be in agreement with water dissolution rates of divalent ions and also with reaction-rate constants of iron carbonate and calcium carbonate reported in the literature.

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Sugita, Kenji, Kazuo Hosoi, Yoshimi Shioda, and Takao Ueha. "Effects of Ca2+ and Mg2+ on ATP-dependent 45Ca2+ influx in A-431 human epidermoidal carcinoma cells." Biochemistry and Cell Biology 69, no. 1 (January 1, 1991): 29–35. http://dx.doi.org/10.1139/o91-004.

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Upon stimulation with 10−6–10−3 M ATP, A-431 human epidermoidal carcinoma cells incorporated radioactive calcium from their medium in a temperature-dependent manner. The rate of incorporation of 45Ca2+ was rapid for the initial 5 min, but decreased immediately thereafter. The preincubation of cells for 2 h in medium depleted of both Ca2+ and Mg2+ abolished the ATP-dependent 45Ca2+ incorporation, irrespective of whether or not the subsequent incubation medium contained Mg2+ ions. ATP-dependent 45Ca2+ incorporation could be restored by a second preincubation (1 h) in medium containing 1 mM Mg2+, but no Ca2+. The Mg2+ ions in the second preincubation medium could be replaced by Ca2+, Co2+, or Cu2+ for restoration of such activity. Elevation of inositol trisphosphate (InsP3) was observed in cells depleted of either Ca2+ or Mg2+, but not in cells depleted of both ions. A parallel effect was observed in changes in [Ca2+]i. Since the concentration of cytosolic calcium ions does not change by incubation of cells in medium depleted of and (or) restored with calcium ions, we conclude that either calcium or magnesium ions associated with some cellular component(s) are responsible for production of InsP3, which then supposedly mobilizes Ca2+ and provokes 45Ca2+ influx.Key words: intracellular calcium ion, inositol trisphosphate, calcium influx.

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Oliveira, Joana S. L., Gerald Brezesinski, Alexandra Hill, and Arne Gericke. "Influence of calcium on ceramide-1-phosphate monolayers." Beilstein Journal of Nanotechnology 7 (February 12, 2016): 236–45. http://dx.doi.org/10.3762/bjnano.7.22.

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Ceramide-1-phosphate (C1P) plays an important role in several biological processes, being identified as a key regulator of many protein functions. For instance, it acts as a mediator of inflammatory responses. The mediation of the inflammation process happens due to the interaction of C1P with the C2 domain of cPLA2α, an effector protein that needs the presence of submicromolar concentrations of calcium ions. The aim of this study was to determine the phase behaviour and structural properties of C1P in the presence and absence of millimolar quantities of calcium in a well-defined pH environment. For that purpose, we used monomolecular films of C1P at the soft air/liquid interface with calcium ions in the subphase. The pH was varied to change the protonation degree of the C1P head group. We used surface pressure versus molecular area isotherms coupled with other monolayer techniques as Brewster angle microscopy (BAM), infrared reflection–absorption spectroscopy (IRRAS) and grazing incidence X-ray diffraction (GIXD). The isotherms indicate that C1P monolayers are in a condensed state in the presence of calcium ions, regardless of the pH. At higher pH without calcium ions, the monolayer is in a liquid-expanded state due to repulsion between the negatively charged phosphate groups of the C1P molecules. When divalent calcium ions are added, they are able to bridge the highly charged phosphate groups, enhancing the regular arrangement of the head groups. Similar solidification of the monolayer structure can be seen in the presence of a 150 times larger concentration of monovalent sodium ions. Therefore, calcium ions have clearly a strong affinity for the phosphomonoester of C1P.

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LeGeros, Racquel Z., Dindo Q. Mijares, J. Park, X. F. Chang, I. Khairoun, Regina Kijkowska, Renata Dias, and John P. LeGeros. "Amorphous Calcium Phosphates (ACP): Formation and Stability." Key Engineering Materials 284-286 (April 2005): 7–10. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.7.

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Our earlier studies showed that several ions inhibit the crystal growth of apatite and promote the formation of amorphous calcium phosphates (ACP). These ions include: magnesium (Mg), zinc (Zn), stannous (Sn), ferrous (Fe), carbonate (CO3), pyrophosphate (P2O7). The purpose of this study was to investigate the effect of combination of these ions (e.g., Mg & CO3, Mg & P2O7, Mg & Zn, etc) on the formation and stability of ACP. ACP compounds containing the different ions were prepared at 25 and 37oC according to the method we previously described. Chemical stability was investigated by suspending the different ACP preparations in solutions with or without inhibitory ions. Thermal stability was determined by sintering the ACP at different temperatures. Dissolution properties were determined in acidic buffer. The ACP before and after chemical or thermal treatment were analyzed using X-ray diffraction, infrared spectroscopy, and thermogravimetry. Results showed synergistic effects of inhibitory ions on the formation of ACP. ACP materials, regardless of their composition, remained amorphous even after heat treatment at 400oC. Transformation of ACP to other calcium phosphate phases depended on the pH and on the solution composition.

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Liao, Si-Ming, Ge Liang, Jing Zhu, Bo Lu, Li-Xin Peng, Qing-Yan Wang, Yu-Tuo Wei, Guo-Ping Zhou, and Ri-Bo Huang. "Influence of Calcium Ions on the Thermal Characteristics of α-amylase from Thermophilic Anoxybacillus sp. GXS-BL." Protein & Peptide Letters 26, no. 2 (February 20, 2019): 148–57. http://dx.doi.org/10.2174/0929866526666190116162958.

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Background: α-Amylases are starch-degrading enzymes and used widely, the study on thermostability of α-amylase is a central requirement for its application in life science and biotechnology. Objective: In this article, our motivation is to study how the effect of Ca2+ ions on the structure and thermal characterization of α-amylase (AGXA) from thermophilic Anoxybacillus sp.GXS-BL. Methods: α-Amylase activity was assayed with soluble starch as the substrate, and the amount of sugar released was determined by DNS method. For AGXA with calcium ions and without calcium ions, optimum temperature (Topt), half-inactivation temperature (T50) and thermal inactivation (halflife, t1/2) was evaluated. The thermal denaturation of the enzymes was determined by DSC and CD methods. 3D structure of AGXA was homology modeled with α-amylase (5A2A) as the template. Results: With calcium ions, the values of Topt, T50, t1/2, Tm and ΔH in AGXA were significantly higher than those of AGXA without calcium ions, showing calcium ions had stabilizing effects on α-amylase structure with the increased temperature. Based on DSC measurements AGXA underwent thermal denaturation by adopting two-state irreversible unfolding processes. Based on the CD spectra, AGXA without calcium ions exhibited two transition states upon unfolding, including α- helical contents increasing, and the transition from α-helices to β-sheet structures, which was obviously different in AGXA with Ca2+ ions, and up to 4 Ca2+ ions were located on the inter-domain or intra-domain regions according to the modeling structure. Conclusion: These results reveal that Ca2+ ions have pronounced influences on the thermostability of AGXA structure.

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Sananmuang, Ratana. "Synthesis of Modified Chitosan with Thiamine Hydrochloride as the Adsorbent for Calcium (II) Ion Removal." Key Engineering Materials 798 (April 2019): 397–403. http://dx.doi.org/10.4028/www.scientific.net/kem.798.397.

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Water quality is very important to food processing industry. Water hardness caused by calcium ions in water can affect the properties of food including aroma, texture, flavor and appearance. Chitosan has amino functional groups that can remove metal ions from aqueous solution. However, chitosan can give more effective removal of calcium ions if it is modified with functionalized substance such as thiamine hydrochloride. therefore, the objectives of this study were to synthesize the modified chitosan with thiamine hydrochloride (MCTH) and to determine its efficiency for removal of calcium ion in solution. Chitosan was prepared from crab shells and modified with thiamine hydrochloride at 30 °C. The morphology of both crab-shell chitosan (CSC) and MCTH was characterized by SEM, FTIR and NMR techniques. Batch adsorption experiments were conducted as a function of pH, contacted time and initial concentration of calcium (II) ions. The desorption of calcium(II) ion from both adsorbents was also investigated. The concentration of calcium in solution was measured by FAAS technique. The results indicated that the optimum pH for adsorption was 6.0 for both CSC and MCTH. The adsorption capacity for MCTH (48.31 mg g-1) was greater than that of CSC (1.52 mg g-1). The isotherm showed that the adsorption process of calcium (II) ions onto MCTH was fitted to Langmuir isotherm model. Calcium desorption from MCTH was lower than that of CSC.

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Song, Mingyue, Leping Dang, and Hongyuan Wei. "Evaluation of Calcium Binding Capacity of Chelating Agents in Calcium Carbonate Suspension and Effects on Calcium Distribution of Calcium Chelating Agents." Australian Journal of Chemistry 74, no. 7 (2021): 557. http://dx.doi.org/10.1071/ch20376.

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In this study, the binding capacity of calcium ions of sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), trisodium citrate (TSC), and potassium oxalate (PO) were evaluated, and the calcium distribution in the presence of STPP and TSPP in CaCl2 solutions (50mmolL−1) were investigated. Under conditions simulating industrial toothpaste, the concentration of fluoride in calcium carbonate suspensions (30 g/50 g) was measured by ion chromatography to investigate the effects of chelating agents on calcium ions. Among all the chelating agents, STPP and TSPP have the highest retention rate of fluoride, indicating better calcium binding capacity. Preliminary studies were carried out in CaCl2 solutions to investigate the influence of concentration and pH on the chelating performance of STPP and TSPP. The distribution of free calcium, chelated calcium, and precipitated calcium in CaCl2 solution in the presence of STPP and TSPP were investigated to reveal two different calcium-chelation mechanisms and laws for STPP and TSPP. This work has a positive guiding significance for the stabilisation of calcium and fluoride in toothpaste formula.

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CRESPO, Mariana Pires, Kamila de Figueiredo PEREIRA, Milton Carlos KUGA, Thiago Soares PORTO, and Luciana ARMADA. "Alkalizing potential and calcium release of residues from intracanal dressing containing calcium hydroxide." Revista de Odontologia da UNESP 47, no. 6 (December 2018): 383–87. http://dx.doi.org/10.1590/1807-2577.11018.

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Abstract Introduction If the restoration, that seal the root canal from oral environment, failed or solubilize, the intracanal dressing could be partially removed, decreasing the efficiency of calcium hydroxide (CH). Objective To evaluate the alkalizing potential and calcium ions release of intracanal residues from different medications, in different periods. Materials and method Human incisors were endodontically instrumented and randomly divided (n=10). The root canals were filled with: G1⎯Calcium hydroxide (CH); G2⎯CH with 0.4% chlorhexidine digluconate (CHC); G3⎯CH with camphorated paramonochlorophenol and glycerin (HPG); G4⎯CH was maintained during all experiment, as positive control group (PC) and G5⎯ No medication was performed in the negative control group (NC). The specimens were immersed in distilled water for 7 days. The intracanal dressing was removed from the experimental groups using F1 instrument (Protaper). The teeth were stored in distilled water for 24 hours, 7, 14 and 28 days. pH value and calcium ions released were evaluated and the data were submitted to ANOVA one-way and Tukey tests. Result All experimental groups presented lower alkalizing potential and calcium ions release than PC (P<0.05). No significant difference was found among the experimental groups, regardless of the period (P>0.05). Conclusion The alkalizing potential and calcium ions release of residues from different intracanal dressing, in different periods, were similar and lower than the positive control group, that the medication was maintained inside the root canal, encouraging the replacement of intracanal dressing when the restoration fail.

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Journal articles on the topic 'Calcium ions'

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