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Journal articles on the topic 'Ion divalent'

Author: Grafiati

Published: 30 November 2024

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1

Nguyen, Hung T., Naoto Hori, and D. Thirumalai. "Theory and simulations for RNA folding in mixtures of monovalent and divalent cations." Proceedings of the National Academy of Sciences 116, no. 42 (September 30, 2019): 21022–30. http://dx.doi.org/10.1073/pnas.1911632116.

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RNA molecules cannot fold in the absence of counterions. Experiments are typically performed in the presence of monovalent and divalent cations. How to treat the impact of a solution containing a mixture of both ion types on RNA folding has remained a challenging problem for decades. By exploiting the large concentration difference between divalent and monovalent ions used in experiments, we develop a theory based on the reference interaction site model (RISM), which allows us to treat divalent cations explicitly while keeping the implicit screening effect due to monovalent ions. Our theory captures both the inner shell and outer shell coordination of divalent cations to phosphate groups, which we demonstrate is crucial for an accurate calculation of RNA folding thermodynamics. The RISM theory for ion–phosphate interactions when combined with simulations based on a transferable coarse-grained model allows us to predict accurately the folding of several RNA molecules in a mixture containing monovalent and divalent ions. The calculated folding free energies and ion-preferential coefficients for RNA molecules (pseudoknots, a fragment of the rRNA, and the aptamer domain of the adenine riboswitch) are in excellent agreement with experiments over a wide range of monovalent and divalent ion concentrations. Because the theory is general, it can be readily used to investigate ion and sequence effects on DNA properties.

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2

Zhang, Huacheng, Xingya Li, Jue Hou, Lei Jiang, and Huanting Wang. "Angstrom-scale ion channels towards single-ion selectivity." Chemical Society Reviews 51, no. 6 (2022): 2224–54. http://dx.doi.org/10.1039/d1cs00582k.

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3

García-Giménez, Elena, Antonio Alcaraz, and Vicente M. Aguilella. "Divalent Metal Ion Transport across Large Biological Ion Channels and Their Effect on Conductance and Selectivity." Biochemistry Research International 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/245786.

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Electrophysiological characterization of large protein channels, usually displaying multi-ionic transport and weak ion selectivity, is commonly performed at physiological conditions (moderate gradients of KCl solutions at decimolar concentrations buffered at neutral pH). We extend here the characterization of the OmpF porin, a wide channel of the outer membrane ofE. coli,by studying the effect of salts of divalent cations on the transport properties of the channel. The regulation of divalent cations concentration is essential in cell metabolism and understanding their effects is of key importance, not only in the channels specifically designed to control their passage but also in other multiionic channels. In particular, in porin channels like OmpF, divalent cations modulate the efficiency of molecules having antimicrobial activity. Taking advantage of the fact that the OmpF channel atomic structure has been resolved both in water and in MgCl2aqueous solutions, we analyze the single channel conductance and the channel selectivity inversion aiming to separate the role of the electrolyte itself, and the counterion accumulation induced by the protein channel charges and other factors (binding, steric effects, etc.) that being of minor importance in salts of monovalent cations become crucial in the case of divalent cations.

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4

Chremos, Alexandros, Matan Mussel, Jack F. Douglas, and Ferenc Horkay. "Ion Partition in Polyelectrolyte Gels and Nanogels." Gels 9, no. 11 (November 7, 2023): 881. http://dx.doi.org/10.3390/gels9110881.

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Polyelectrolyte gels provide a load-bearing structural framework for many macroscopic biological tissues, along with the organelles within the cells composing tissues and the extracellular matrices linking the cells at a larger length scale than the cells. In addition, they also provide a medium for the selective transportation and sequestration of ions and molecules necessary for life. Motivated by these diverse problems, we focus on modeling ion partitioning in polyelectrolyte gels immersed in a solution with a single type of ionic valence, i.e., monovalent or divalent salts. Specifically, we investigate the distribution of ions inside the gel structure and compare it with the bulk, i.e., away from the gel structure. In this first exploratory study, we neglect solvation effects in our gel by modeling the gels without an explicit solvent description, with the understanding that such an approach may be inadequate for describing ion partitioning in real polyelectrolyte gels. We see that this type of model is nonetheless a natural reference point for considering gels with solvation. Based on our idealized polymer network model without explicit solvent, we find that the ion partition coefficients scale with the salt concentration, and the ion partition coefficient for divalent ions is higher than for monovalent ions over a wide range of Bjerrum length (lB) values. For gels having both monovalent and divalent salts, we find that divalent ions exhibit higher ion partition coefficients than monovalent salt for low divalent salt concentrations and low lB. However, we also find evidence that the neglect of an explicit solvent, and thus solvation, provides an inadequate description when compared to experimental observations. Thus, in future work, we must consider both ion and polymer solvation to obtain a more realistic description of ion partitioning in polyelectrolyte gels.

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5

Onoe, Sakura, Myu Yoshida, Naoya Terahara, and Yoshiyuki Sowa. "Coupling Ion Specificity of the Flagellar Stator Proteins MotA1/MotB1 of Paenibacillus sp. TCA20." Biomolecules 10, no. 7 (July 20, 2020): 1078. http://dx.doi.org/10.3390/biom10071078.

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The bacterial flagellar motor is a reversible rotary molecular nanomachine, which couples ion flux across the cytoplasmic membrane to torque generation. It comprises a rotor and multiple stator complexes, and each stator complex functions as an ion channel and determines the ion specificity of the motor. Although coupling ions for the motor rotation were presumed to be only monovalent cations, such as H+ and Na+, the stator complex MotA1/MotB1 of Paenibacillus sp. TCA20 (MotA1TCA/MotB1TCA) was reported to use divalent cations as coupling ions, such as Ca2+ and Mg2+. In this study, we initially aimed to measure the motor torque generated by MotA1TCA/MotB1TCA under the control of divalent cation motive force; however, we identified that the coupling ion of MotA1TCAMotB1TCA is very likely to be a monovalent ion. We engineered a series of functional chimeric stator proteins between MotB1TCA and Escherichia coli MotB. E. coli ΔmotAB cells expressing MotA1TCA and the chimeric MotB presented significant motility in the absence of divalent cations. Moreover, we confirmed that MotA1TCA/MotB1TCA in Bacillus subtilis ΔmotABΔmotPS cells generates torque without divalent cations. Based on two independent experimental results, we conclude that the MotA1TCA/MotB1TCA complex directly converts the energy released from monovalent cation flux to motor rotation.

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6

Zheng, Alvin Lim Teik, Supakorn Boonyuen, Teruhisa Ohno, and Yoshito Andou. "Hydrothermally Reduced Graphene Hydrogel Intercalated with Divalent Ions for Dye Adsorption Studies." Processes 9, no. 1 (January 18, 2021): 169. http://dx.doi.org/10.3390/pr9010169.

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Fundamental studies involving divalent ion intercalated graphene-based hydrogel are still lacking in terms of their adsorption behavior towards dye pollutants. In this study, we prepared a self-assembled Mg2+ and Ca2+ intercalated reduced graphene hydrogel (rGH) using hydrothermal treatment to evaluate the intercalation impact on the adsorption capability towards cationic dyes, methylene blue and rhodamine B. The morphological, structural, thermal, and textural properties of the divalent ion intercalated reduced graphene hydrogels were studied using Fourier transform infrared spectrometer, thermogravimetric analysis, Raman spectroscopy, scanning electron microscope-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. The increased adsorption capacity of the divalent ion intercalated reduced graphene-based hydrogels towards the dye molecules resulted from the increase in the specific surface area and pore volume due to the Mg2+ and Ca2+ bridging that formed spaces between the graphene sheets framework. Adsorption kinetics and the equilibrium adsorption isotherm were fitted by a pseudo-second-order alongside intraparticle diffusion kinetic models and Langmuir isotherm respectively. In addition, the divalent ion intercalated reduced graphene hydrogel showed good generation after three cycles of simultaneous adsorption.

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7

Hutchison, Alastair J. "Predialysis management of divalent ion metabolism." Kidney International 56 (December 1999): 82–84. http://dx.doi.org/10.1046/j.1523-1755.1999.07306.x.

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8

Madrigal González, Blanca, Graham Christie, Colin A. B. Davidson, Jeff Blyth, and Christopher R. Lowe. "Divalent metal ion-sensitive holographic sensors." Analytica Chimica Acta 528, no. 2 (January 2005): 219–28. http://dx.doi.org/10.1016/j.aca.2004.03.029.

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9

Nasi, Enrico, and Maria del Pilar Gomez. "Divalent Cation Interactions with Light-Dependent K Channels." Journal of General Physiology 114, no. 5 (October 11, 1999): 653–72. http://dx.doi.org/10.1085/jgp.114.5.653.

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The light-dependent K conductance of hyperpolarizing Pecten photoreceptors exhibits a pronounced outward rectification that is eliminated by removal of extracellular divalent cations. The voltage-dependent block by Ca2+ and Mg2+ that underlies such nonlinearity was investigated. Both divalents reduce the photocurrent amplitude, the potency being significantly higher for Ca2+ than Mg2+ (K1/2 ≈ 16 and 61 mM, respectively, at Vm = −30 mV). Neither cation is measurably permeant. Manipulating the concentration of permeant K ions affects the blockade, suggesting that the mechanism entails occlusion of the permeation pathway. The voltage dependency of Ca2+ block is consistent with a single binding site located at an electrical distance of δ ≈ 0.6 from the outside. Resolution of light-dependent single-channel currents under physiological conditions indicates that blockade must be slow, which prompted the use of perturbation/relaxation methods to analyze its kinetics. Voltage steps during illumination produce a distinct relaxation in the photocurrent (τ = 5–20 ms) that disappears on removal of Ca2+ and Mg2+ and thus reflects enhancement or relief of blockade, depending on the polarity of the stimulus. The equilibration kinetics are significantly faster with Ca2+ than with Mg2+, suggesting that the process is dominated by the “on” rate, perhaps because of a step requiring dehydration of the blocking ion to access the binding site. Complementary strategies were adopted to investigate the interaction between blockade and channel gating: the photocurrent decay accelerates with hyperpolarization, but the effect requires extracellular divalents. Moreover, conditioning voltage steps terminated immediately before light stimulation failed to affect the photocurrent. These observations suggest that equilibration of block at different voltages requires an open pore. Inducing channels to close during a conditioning hyperpolarization resulted in a slight delay in the rising phase of a subsequent light response; this effect can be interpreted as closure of the channel with a divalent ion trapped inside.

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10

Aiken, ML, MH Ginsberg, and EF Plow. "Divalent cation-dependent and independent surface expression of thrombospondin on thrombin-stimulated human platelets." Blood 69, no. 1 (January 1, 1987): 58–64. http://dx.doi.org/10.1182/blood.v69.1.58.58.

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Abstract Thrombospondin (TSP), a platelet alpha-granule protein, becomes expressed on the surface of thrombin-stimulated platelets. The surface expression of this protein occurs through two distinct mechanisms. At low platelet concentrations (1 X 10(8)/mL), a divalent ion-dependent, low-capacity mechanism predominates. At higher cell concentrations, a divalent ion-dependent, higher capacity mechanism prevails that can account for greater than 90% of all the TSP surface expression measured. This mechanism requires the presence of both calcium and magnesium (Ca + Mg). The dependence of the divalent ion-dependent surface expression on platelet concentration suggests that release of the molecule from the cell followed by its binding to the cell surface mediates this component of the endogenous TSP-platelet interaction. These data are consistent with a two-receptor model for the platelet- surface expression of the endogenous TSP pool.

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11

Aiken, ML, MH Ginsberg, and EF Plow. "Divalent cation-dependent and independent surface expression of thrombospondin on thrombin-stimulated human platelets." Blood 69, no. 1 (January 1, 1987): 58–64. http://dx.doi.org/10.1182/blood.v69.1.58.bloodjournal69158.

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Thrombospondin (TSP), a platelet alpha-granule protein, becomes expressed on the surface of thrombin-stimulated platelets. The surface expression of this protein occurs through two distinct mechanisms. At low platelet concentrations (1 X 10(8)/mL), a divalent ion-dependent, low-capacity mechanism predominates. At higher cell concentrations, a divalent ion-dependent, higher capacity mechanism prevails that can account for greater than 90% of all the TSP surface expression measured. This mechanism requires the presence of both calcium and magnesium (Ca + Mg). The dependence of the divalent ion-dependent surface expression on platelet concentration suggests that release of the molecule from the cell followed by its binding to the cell surface mediates this component of the endogenous TSP-platelet interaction. These data are consistent with a two-receptor model for the platelet- surface expression of the endogenous TSP pool.

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12

Chen, Mengzhu, Fang Wu, Linwen Yu, Yuxin Cai, Hang Chen, and Mingtao Zhang. "Chloride binding capacity of LDHs with various divalent cations and divalent to trivalent cation ratios in different solutions." CrystEngComm 21, no. 44 (2019): 6790–800. http://dx.doi.org/10.1039/c9ce01322a.

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Chlorides were bonded by LDHs due to ion exchange and surface adsorption. Carbonation resulted in the debonding of the chloride bond by ion exchange, however, surface adsorption was not affected by carbonation.

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13

Katzka, D. A., R. Cox, A. J. Davidoff, and M. Morad. "Permeation of divalent cations through the Ca2+ channel of rabbit portal vein myocytes." American Journal of Physiology-Heart and Circulatory Physiology 262, no. 2 (February 1, 1992): H326—H330. http://dx.doi.org/10.1152/ajpheart.1992.262.2.h326.

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The divalent selectivity of the Ca2+ channel in the rabbit portal vein myocyte was examined by the whole cell clamp method. A concentration-dependent selectivity of divalent ion permeation was found such that when Ca2+ was replaced by Ba2+ or Sr2+, the order of maximum current was Ca2+ = Ba2+ greater than Sr2+ at 2 mM and Ba2+ greater than Sr2+ greater than or equal to Ca2+ at 5-10 mM. The possibility of block of the Ca2+ channel by micromolar concentrations of "contaminant" Ca2+ as a determinant of change in the order of selectivity of divalents was examined. Ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (500 microM) significantly increased maximum Ba2+ current (IBa) or ISr in solution containing 5 mM Ba2+ or Sr2+. Furthermore, at 5 mM extracellular Ba2+ concentration, addition of 10, 20, 50, and 100 microM Ca2+ caused a 6, 14, 22, and 33% decrease in IBa, respectively. These results suggest that the portal vein Ca2+ channel has three orders of magnitude higher selectivity for Ca2+ over Ba2+ and Sr2+ such that micromolar Ca2+ may block permeation of other divalents through the channel.

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14

Su, Jingcang, Yong Pei, Zhenhua Yang, and Xianyou Wang. "First-principles investigation on the structural, electronic properties and diffusion barriers of Mg/Al doped NaCoO2as the cathode material of rechargeable sodium batteries." RSC Advances 5, no. 35 (2015): 27229–34. http://dx.doi.org/10.1039/c5ra01895a.

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15

Nguyen, Dung, Hwoi Kwon, and Tsung-Yu Chen. "Divalent Cation Modulation of Ion Permeation in TMEM16 Proteins." International Journal of Molecular Sciences 22, no. 4 (February 23, 2021): 2209. http://dx.doi.org/10.3390/ijms22042209.

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Intracellular divalent cations control the molecular function of transmembrane protein 16 (TMEM16) family members. Both anion channels (such as TMEM16A) and phospholipid scramblases (such as TMEM16F) in this family are activated by intracellular Ca2+ in the low µM range. In addition, intracellular Ca2+ or Co2+ at mM concentrations have been shown to further potentiate the saturated Ca2+-activated current of TMEM16A. In this study, we found that all alkaline earth divalent cations in mM concentrations can generate similar potentiation effects in TMEM16A when applied intracellularly, and that manipulations thought to deplete membrane phospholipids weaken the effect. In comparison, mM concentrations of divalent cations minimally potentiate the current of TMEM16F but significantly change its cation/anion selectivity. We suggest that divalent cations may increase local concentrations of permeant ions via a change in pore electrostatic potential, possibly acting through phospholipid head groups in or near the pore. Monovalent cations appear to exert a similar effect, although with a much lower affinity. Our findings resolve controversies regarding the ion selectivity of TMEM16 proteins. The physiological role of this mechanism, however, remains elusive because of the nearly constant high cation concentrations in cytosols.

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16

Cook, Paul F., and William E. Karsten. "Pyridine nucleotide-dependent (3-hydroxyacid oxidative decarboxylases: An overview." Protein & Peptide Letters 7, no. 5 (October 2000): 281–86. http://dx.doi.org/10.2174/092986650705221207142048.

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Abstract: The class of pyridine nucleotide-dependent -hydroxyacid oxidative decarboxylases generally catalyze the oxidative decarboxylation of a -hydroxyacid to a ketone and CO2 using NAD(Pt as the oxidant. There are two subclasses based on the metalsdependence of the reaction. Enzymes that have substrates with electron withdrawing substituents in the a- and or y-position generally do not require a metal ion cofactor, an example is 6-phosphogluconate dehydrogenase. Of the remaining enzymes, some require only a divalent metal ion; e.g. malic enzyme, while the others require both a monovalent and a divalent metal ion, for example tartate dehydrogenase.

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17

Hassan, Refat M., S. A. El-Shatoury, and M. Th Makhlouf. "Alginate Polyelectrolyte Ionotropic Gels-XII. Chromatographic Separation of Divalent Transition Metal Ions using Alginates as Ion Exchangers." High Performance Polymers 4, no. 1 (February 1992): 49–54. http://dx.doi.org/10.1088/0954-0083/4/1/006.

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The separation of divalent metal ion mixtures has been investigated chromatographically on columns of either gel or sol forms of alginate polyelectrolyte. Separation was obtained in the form of narrow sharp zones for the metal ions. Ion exchange selectivity indicated that Cu2+ ions were most strongly retained among the divalent metal ions studied. The factors which affect the ion exchange selectivity, such as the strength of chelation and the mobility and radii of the metal ions, are discussed. The selectivity coefficient for the separation of a mixture of Cu2+ and Co2+ ions on columns of calcium alginate gel or sodium alginate sol was determined and found to be 1.9 ± 0.1 in both ion exchangers at 25°C.

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18

Zuo, Pengjian, and Geping Yin. "Chelated electrolytes for divalent metal ions." Science 374, no. 6564 (October 8, 2021): 156. http://dx.doi.org/10.1126/science.abi6643.

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19

Huang, Yuting, and Eric D. Dodds. "Ion-neutral collisional cross sections of carbohydrate isomers as divalent cation adducts and their electron transfer products." Analyst 140, no. 20 (2015): 6912–21. http://dx.doi.org/10.1039/c5an01093d.

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20

Tang, Yuanqiang, Yunguo Liu, Tao Zhang, Jiang Li, Xiaohua Wang, Wei Zhang, Guangming Zeng, Shaobo Liu, and Lei Guan. "Acute Toxicity of Divalent Mercury Ion to Anguilla japonica from Seawater and Freshwater Aquaculture and Its Effects on Tissue Structure." International Journal of Environmental Research and Public Health 16, no. 11 (June 3, 2019): 1965. http://dx.doi.org/10.3390/ijerph16111965.

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The acute toxicity of divalent mercury ion to Anguilla japonica from seawater and freshwater aquaculture was assessed. In particular, the effects of toxicity on the microstructures of the gill and liver tissues were examined using the hydrostatic method, without feeding, at a water temperature of 20 °C. The median lethal concentrations (LC50) of divalent mercury ion to fishes in seawater and freshwater over various durations were: 24 h = 1.637 and 1.428 mg/L; 48 h = 1.562 and 1.377 mg/L; 72 h = 1.530 and 1.284 mg/L; and 96 h = 1.442 and 1.228 mg/L. The safety mass concentrations were 0.1442 and 0.01228 mg/L, respectively. After exposure to divalent mercury ion, adhesion between the gill lamellae and massive cellular disintegration and necrotic shedding were observed in the gill tissue sections. The liver tissues underwent hyperemia and swelling, with the appearance of blood spots, swelling of the hepatocyte mitochondria, dilation of the rough endoplasmic reticulum, and intercellular inflation.

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21

Tinker, A., and A. J. Williams. "Divalent cation conduction in the ryanodine receptor channel of sheep cardiac muscle sarcoplasmic reticulum." Journal of General Physiology 100, no. 3 (September 1, 1992): 479–93. http://dx.doi.org/10.1085/jgp.100.3.479.

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The conduction properties of the alkaline earth divalent cations were determined in the purified sheep cardiac sarcoplasmic reticulum ryanodine receptor channel after reconstitution into planar phospholipid bilayers. Under bi-ionic conditions there was little difference in permeability among Ba2+, Ca2+, Sr2+, and Mg2+. However, there was a significant difference between the divalent cations and K+, with the divalent cations between 5.8- and 6.7-fold more permeant. Single-channel conductances were determined under symmetrical ionic conditions with 210 mM Ba2+ and Sr2+ and from the single-channel current-voltage relationship under bi-ionic conditions with 210 mM divalent cations and 210 mM K+. Single-channel conductance ranged from 202 pS for Ba2+ to 89 pS for Mg2+ and fell in the sequence Ba2+ greater than Sr2+ greater than Ca2+ greater than Mg2+. Near-maximal single-channel conductance is observed at concentrations as low as 2 mM Ba2+. Single-channel conductance and current measurements in mixtures of Ba(2+)-Mg2+ and Ba(2+)-Ca2+ reveal no anomalous behavior as the mole fraction of the ions is varied. The Ca(2+)-K+ reversal potential determined under bi-ionic conditions was independent of the absolute value of the ion concentrations. The data are compatible with the ryanodine receptor channel acting as a high conductance channel displaying moderate discrimination between divalent and monovalent cations. The channel behaves as though ion translocation occurs in single file with at most one ion able to occupy the conduction pathway at a time.

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22

Rocklin, R. D., M. A. Rey, J. R. Stillian, and D. L. Campbell. "Ion Chromatography of Monovalent and Divalent Cations." Journal of Chromatographic Science 27, no. 8 (August 1, 1989): 474–79. http://dx.doi.org/10.1093/chromsci/27.8.474.

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23

Martinolich, Andrew J., Cheng-Wei Lee, I.-Te Lu, Sarah C. Bevilacqua, Molleigh B. Preefer, Marco Bernardi, André Schleife, and Kimberly A. See. "Solid-State Divalent Ion Conduction in ZnPS3." Chemistry of Materials 31, no. 10 (March 15, 2019): 3652–61. http://dx.doi.org/10.1021/acs.chemmater.9b00207.

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24

Reddy, K. Veera, Alan R. Jacobson, John I. Kung, and Lawrence M. Sayre. "Divalent metal ion catalyzed hydrolysis of picolinanilides." Inorganic Chemistry 30, no. 18 (September 1991): 3520–25. http://dx.doi.org/10.1021/ic00018a024.

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25

Haynes, L. W. "Permeation and block by internal and external divalent cations of the catfish cone photoreceptor cGMP-gated channel." Journal of General Physiology 106, no. 3 (September 1, 1995): 507–23. http://dx.doi.org/10.1085/jgp.106.3.507.

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The ability of the divalent cations calcium, magnesium, and barium to permeate through the cGMP-gated channel of catfish cone outer segments was examined by measuring permeability and conductance ratios under biionic conditions and by measuring their ability to block current carried by sodium when presented on the cytoplasmic or extracellular side of the channel. Current carried by divalent cations in the absence of monovalent cations showed the typical rectification pattern observed from these channels under physiological conditions (an exponential increase in current at both positive and negative voltages). With calcium as the reference ion, the relative permeabilities were Ca > Ba > Mg, and the chord conductance ratios at +50 mV were in the order of Ca approximately Mg > Ba. With external sodium as the reference ion, the relative permeabilities were Ca > Mg > Ba > Na with chord conductance ratios at +30 mV in the order of Na > Ca = Mg > Ba. The ability of divalent cations presented on the intracellular side to block the sodium current was in the order Ca > Mg > Ba at +30 mV and Ca > Ba > Mg at -30 mV. Block by external divalent cations was also investigated. The current-voltage relations showed block by internal divalent cations reveal no anomalous mole fraction behavior, suggesting little ion-ion interaction within the pore. An Eyring rate theory model with two barriers and a single binding site is sufficient to explain both these observations and those for monovalent cations, predicting a single-channel conductance under physiological conditions of 2 pS and an inward current at -30 mV carried by 82% Na, 5% Mg, and 13% Ca.

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26

Nakajima, Tomohiko, Megumi Kanaori, Hiroyuki Tateno, Junichi Nomoto, Yugo Miseki, Tetsuo Tsuchiya, and Kazuhiro Sayama. "Diffusion controlled porous WO3 thin film photoanodes for efficient solar-driven photoelectrochemical permanganic acid production." Sustainable Energy & Fuels 3, no. 9 (2019): 2380–90. http://dx.doi.org/10.1039/c9se00253g.

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Photoelectrochemical (PEC) oxidation of the divalent manganese ion to the permanganate ion was achieved by using porous WO₃ thin film photoanodes in sulfuric acid electrolytes under simulated sunlight.

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27

Walkowiak, Jacek J., Rohit Nikam, and Matthias Ballauff. "Adsorption of Mono- and Divalent Ions onto Dendritic Polyglycerol Sulfate (dPGS) as Studied Using Isothermal Titration Calorimetry." Polymers 15, no. 13 (June 23, 2023): 2792. http://dx.doi.org/10.3390/polym15132792.

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The effective charge of highly charged polyelectrolytes is significantly lowered by a condensation of counterions. This effect is more pronounced for divalent ions. Here we present a study of the counterion condensation to dendritic polyglycerol sulfate (dPGS) that consists of a hydrophilic dendritic scaffold onto which sulfate groups are appended. The interactions between the dPGS and divalent ions (Mg2+ and Ca2+) were analyzed using isothermal titration calorimetry (ITC) and showed no ion specificity upon binding, but clear competition between the monovalent and divalent ions. Our findings, in line with the latest theoretical studies, demonstrate that a large fraction of the monovalent ions is sequentially replaced with the divalent ions.

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28

Hebert, S. C., E. M. Brown, and H. W. Harris. "Role of the Ca(2+)-sensing receptor in divalent mineral ion homeostasis." Journal of Experimental Biology 200, no. 2 (January 1, 1997): 295–302. http://dx.doi.org/10.1242/jeb.200.2.295.

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The divalent mineral cations Ca2+ and Mg2+ play many and diverse roles both in the function of cells and in extracellular processes. The metabolism of these cations is a complex process involving the coordinated function of several organ systems and endocrine glands. A recently cloned G-protein-coupled receptor responds to extracellular calcium concentration (Ca2+0-sensing receptor, CaSR) and mediates several of the known effects of Ca2+0 on parathyroid and renal function. The CaSR, which is also expressed in a number of other tissues including thyroidal C-cells, brain and gastrointestinal tract, may function as a Ca2+0 sensor in these tissues as well. Thus, Ca2+0 is a first messenger (or hormone) which, via CaSR-mediated activation of second messenger systems (e.g. phospholipases C and A2, cyclic AMP) leads to altered function of these cells. Several mutations in the human CaSR gene have been identified and shown to cause three inherited diseases of calcium homeostasis, clearly implicating the CaSR as an important component of the homeostatic mechanism for divalent mineral ions. Ca2+ and Mg2+ losses from the body are regulated by altering the urinary excretion of these divalent cations. The localization of the CaSR transcripts and protein in the kidney not only provides a basis for a direct Ca2+0 (or Mg2+0)-mediated regulation of Ca2+ (and Mg2+) excretion but also suggests a functional link between divalent mineral and water metabolism. In the kidney, the thick ascending limb of Henle (TAL) plays crucial roles in regulating both divalent mineral reabsorption and urine concentration. Recent studies have suggested models whereby extracellular Ca2+, via the CaSR expressed in the TAL as well as in the collecting duct system, modulates both Ca2+ 0 and Mg2+ 0 as well as water reabsorbtion. When taken together, these studies suggest that the CaSR not only provides the primary mechanism for Ca2+ 0-mediated regulation of parathyroid hormone secretion from parathyroid glands but also for direct modulation of renal divalent mineral excretion and urinary concentrating ability. These latter functions may furnish a mechanism for integrating and balancing water and divalent cation losses that minimizes the risk of urinary tract stone formation. This mechanism can explain hypercalcemia-mediated polyuria (diabetes insipidus).

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29

Mandal, Suraj Kumar, and Shankar Prasad Kanaujia. "Structural and thermodynamic insights into a novel Mg²⁺–citrate-binding protein from the ABC transporter superfamily." Acta Crystallographica Section D Structural Biology 77, no. 12 (November 11, 2021): 1516–34. http://dx.doi.org/10.1107/s2059798321010457.

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More than one third of proteins require metal ions to accomplish their functions, making them obligatory for the growth and survival of microorganisms in varying environmental niches. In prokaryotes, besides their involvement in various cellular and physiological processes, metal ions stimulate the uptake of citrate molecules. Citrate is a source of carbon and energy and is reported to be transported by secondary transporters. In Gram-positive bacteria, citrate molecules are transported in complex with divalent metal ions, whereas in Gram-negative bacteria they are translocated by Na+/citrate symporters. In this study, the presence of a novel divalent-metal-ion-complexed citrate-uptake system that belongs to the primary active ABC transporter superfamily is reported. For uptake, the metal-ion-complexed citrate molecules are sequestered by substrate-binding proteins (SBPs) and transferred to transmembrane domains for their transport. This study reports crystal structures of an Mg2+–citrate-binding protein (MctA) from the Gram-negative thermophilic bacterium Thermus thermophilus HB8 in both apo and holo forms in the resolution range 1.63–2.50 Å. Despite binding various divalent metal ions, MctA possesses the coordination geometry to bind its physiological metal ion, Mg2+. The results also suggest an extended subclassification of cluster D SBPs, which are known to bind and transport divalent-metal-ion-complexed citrate molecules. Comparative assessment of the open and closed conformations of the wild-type and mutant MctA proteins suggests a gating mechanism of ligand entry following an `asymmetric domain movement' of the N-terminal domain for substrate binding.

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30

Blanchard, Darian J. M., and Richard A. Manderville. "An internal charge transfer-DNA platform for fluorescence sensing of divalent metal ions." Chemical Communications 52, no. 61 (2016): 9586–88. http://dx.doi.org/10.1039/c6cc04613d.

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31

Malik, Anjali, Harvijay Singh, Akshay Pareek, and Shailly Tomar. "Biochemical and biophysical insights into the metal binding spectrum and bioactivity of arginase of Entamoeba histolytica." Metallomics 10, no. 4 (2018): 623–38. http://dx.doi.org/10.1039/c8mt00002f.

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32

Ariponnammal, S., and S. Natarajan. "High Pressure Electrical Resistivity Study of Sm0.85Nd0.15Se." Modern Physics Letters B 11, no. 26n27 (November 20, 1997): 1189–92. http://dx.doi.org/10.1142/s0217984997001420.

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The study of rare-earth monochalcogenides have received much attention because of their interesting electrical properties. They crystallize in the NaCl type structure and are semiconducting if the rare earth ion is in the divalent state and metalic if trivalent state. The effect of substitution of trivalent rare earth ion in divalent rare earth has been studied. We present the results of electrical resistivity measurements and lattice parameter study on Sm0.85Nd0.15Se . The structure of the sample is confirmed by the theoretical calculation of X-ray intensities using Lazy-Pulverix programme. The electrical resistivity is found to be decreasing with the increase of pressure.

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33

Heath, Jennifer, Hungru Chen, and M. Saiful Islam. "MgFeSiO4 as a potential cathode material for magnesium batteries: ion diffusion rates and voltage trends." Journal of Materials Chemistry A 5, no. 25 (2017): 13161–67. http://dx.doi.org/10.1039/c7ta03201c.

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Developing rechargeable magnesium batteries has become an area of growing interest as an alternative to lithium-ion batteries largely due to their potential to offer increased energy density from the divalent charge of the Mg ion.

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34

Zulueta, Yohandys A., and Minh Tho Nguyen. "Enhanced Li-ion transport in divalent metal-doped Li2SnO3." Dalton Transactions 50, no. 8 (2021): 3020–26. http://dx.doi.org/10.1039/d0dt03860a.

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35

Laver, D. R. "Divalent cation block and competition between divalent and monovalent cations in the large-conductance K+ channel from Chara australis." Journal of General Physiology 100, no. 2 (August 1, 1992): 269–300. http://dx.doi.org/10.1085/jgp.100.2.269.

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The patch-clamp technique is used to investigate divalent ion block of the large-conductance K+ channel from Chara australis. Block by Ba2+, Ca2+, Mg2+, and Pt(NH3)4(2+) from the vacuolar and cytoplasmic sides is used to probe the structure of, and ion interactions within, the pore. Five divalent ion binding sites are detected. Vacuolar Ca2+ reduces channel conductance by binding to a site located 7% along the membrane potential difference (site 1, delta = 0.07; from the vacuolar side); it also causes channel closures with mean a duration of approximately 0.1-1 ms by binding at a deeper site (site 2, delta = 0.3). Ca2+ can exit from site 2 into both the vacuolar and cytoplasmic solutions. Cytoplasmic Ca2+ reduces conductance by binding at two sites (site 3, delta = -0.21; site 4, delta = -0.6; from the cytoplasmic side) and causes closures with a mean duration of 10-100 ms by binding to site 5 (delta = -0.7). The deep sites exhibit stronger ion specificity than the superficial sites. Cytoplasmic Ca2+ binds sequentially to sites 3-5 and Ca2+ at site 5 can be locked into the pore by a second Ca2+ at site 3 or 4. Ca2+ block is alleviated by increasing [K+] on the same side of the channel. Further, Ca2+ occupancy of the deep sites (2, 4, and 5) is reduced by K+, Rb+, NH4+, and Na+ on the opposite side of the pore. Their relative efficacy correlates with their relative permeability in the channel. While some Ca2+ and K+ sites compete for ions, Ca2+ and K+ can simultaneously occupy the channel. Ca2+ binding at site 1 only partially blocks channel conduction. The results suggest the presence of four K+ binding sites on the channel protein. One cytoplasmic facing site has an equilibrium affinity of 10 mM (site 6, delta = -0.3) and one vacuolar site (site 7, delta less than 0.2) has low affinity (greater than 500 mM). Divalent ion block of the Chara channel shows many similarities to that of the maxi-K channel from rat skeletal muscle.

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36

Yoshida, N., T. Naito, and H. Fujishiro. "Thermoelectric properties of Li-doped Cu0.95-xM0.05LixO (M=Mn, Ni, Zn)." MRS Proceedings 1490 (2012): 69–73. http://dx.doi.org/10.1557/opl.2012.1571.

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ABSTRACTThermoelectric properties of the Li-doped Cu0.95-xM0.05LixO (M=divalent metal ion; Mn, Ni, Zn) were investigated at the temperature up to 1273 K. In the doped divalent metal ions, Zn2+ ion was the most effective to reduce the thermal conductivity, and the Ni2+ substitution was preferable to decrease the electrical resistivity. For the Cu0.95-xNi0.05LixO sample at x=0.03, the maxima of the dimensionless thermoelectric figure of merit ZT and the power factor P at 1246 K were 4.2×10-2 and 1.6 ×10-4 W/K2m, respectively. The enhancement of the thermoelectric properties of the Li-doped Cu0.95-xM0.05LixO system was discussed.

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Vinnik, Denis, Santhoshkumar Mahadevan, and Puneet Sharma. "Magnetic Study on Divalent Ion Substituted Barium Hexaferrites." Defect and Diffusion Forum 410 (August 17, 2021): 714–19. http://dx.doi.org/10.4028/www.scientific.net/ddf.410.714.

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Magnetic properties of Co, Ni and Zn substituted barium hexaferrite (BaM) samples prepared by solid state ceramic method were studied. Saturation magnetisation were found higher for Zn-substituted BaM, whereas, coercivity is higher for Co2+ and Ni2+ ion substituted samples. Anisotropy field for all substituted samples was calculated by the law of approaching saturation. Remanence, squareness and thermomagnetic plot suggest Zn2+ ions restricts the magnetic interaction of various sites in BaM.

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Morgenstern, Travis J., Arden Darko-Boateng, Papiya Choudhury, Sri Karthika Shanmugam, Xinle Zou, and Henry M. Colecraft. "Bidirectional modulation of ion channels with divalent nanobodies." Biophysical Journal 121, no. 3 (February 2022): 385a. http://dx.doi.org/10.1016/j.bpj.2021.11.819.

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39

Zhang, Wen, Li-Zhuang Chen, Ren-Gen Xiong, Takayoshi Nakamura, and Songping D. Huang. "New Ferroelectrics Based on Divalent Metal Ion Alum." Journal of the American Chemical Society 131, no. 35 (September 9, 2009): 12544–45. http://dx.doi.org/10.1021/ja905399x.

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Fife, Thomas H., and Mahesh P. Pujari. "Divalent metal ion catalyzed reactions of acyl phosphates." Journal of the American Chemical Society 112, no. 14 (July 1990): 5551–57. http://dx.doi.org/10.1021/ja00170a020.

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Scott, R. H., S. M. McGuirk, and A. C. Dolphin. "Modulation of divalent cation-activated chloride ion currents." British Journal of Pharmacology 94, no. 3 (July 1988): 653–62. http://dx.doi.org/10.1111/j.1476-5381.1988.tb11572.x.

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42

Malashkevich, G. E., A. G. Bazylev, A. L. Blinov, M. A. Borik, A. P. Voitovich, V. S. Kalinov, and V. N. Tadéush. "Sensitization of neodymium ion luminescence by divalent tin." Soviet Journal of Quantum Electronics 21, no. 6 (June 30, 1991): 601–5. http://dx.doi.org/10.1070/qe1991v021n06abeh003893.

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43

Sankar, G., J. M. Thomas, J. Chen, P. A. Wright, P. A. Barrett, G. N. Greaves, and C. R. A. Catlow. "EXAFS investigation of divalent metal ion substituted AlPOs." Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 97, no. 1-4 (May 1995): 37–40. http://dx.doi.org/10.1016/0168-583x(94)00356-4.

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44

Copes, W. E., G. A. Chastaganer, and R. L. Hummel. "Activity of Chlorine Dioxide in a Solution of Ions and pH Against Thielaviopsis basicola and Fusarium oxysporum." Plant Disease 88, no. 2 (February 2004): 188–94. http://dx.doi.org/10.1094/pdis.2004.88.2.188.

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Chlorine dioxide (ClO2) is a disinfestant used to control pathogens in water. To determine if interactions between inorganic ions and pH levels effect ClO2 activity in vitro, concentrations of ClO2 (0, 1, 3, 5, 7, 9, 22, 24, 46, 58, and 70 mg/liter) were mixed for 10 min in solutions containing a nitrogen and hard water solution with equal concentrations of ammonium, nitrate, and synthetic hard water (0 and 100 mg/liter) and a divalent metal ion solution with equal concentrations of copper, iron, manganese, and zinc (0, 1, 3, and 5 mg/liter) at pH 5 and 8. Macro- and microconidia of Fusarium oxysporum f. sp. narcissi or conidia and aleuriospores of Thielaviopsis basicola were injected into each suspension for 30 s, captured on filter paper disks that were flushed with water, and plated on 50% potato dextrose agar. Spore germination was quantified after 1 day. ClO2 activity had a similar effect on both fungal species and all types of propagules with interactions among the divalent metal ion solution, nitrogen and hard water solution, and pH treatments. A higher concentration of ClO2 was required at pH 8 than at pH 5 to achieve a lethal dose resulting in 50% mortality of spores (LD50). The addition of the divalent metal ion solution required an increase in ClO2 concentration to maintain a LD50. When combined with the nitrogen and hard water solution, the divalent metal ion solution placed a higher demand on ClO2 at pH 5 and a lower demand on ClO2 at pH 8, thus requiring an increase and decrease in a ClO2 concentration, respectively, to achieve a LD50. Chlorine dioxide doses resulting in 50% mortality ranged from 0.5 to 7.0 mg/liter for conidia of F. oxysporum, 0.5 to 11.9 mg/liter for conidia of T. basicola, and 15.0 to 45.5 mg/liter for aleuriospores of T. basicola.

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45

Susanto, Heru, Meike Fitrianingtyas, I. Nyoman Widiasa, Titik Istirokhatun, Yunita Fahni, and Assalaam Abdurahman. "The Role of Membrane, Feed characteristic and Process Parameter on RED Power Generation." International Journal of Renewable Energy Development 12, no. 1 (December 20, 2022): 203–8. http://dx.doi.org/10.14710/ijred.2023.49775.

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Reverse electrodialysis (RED) is a renewable energy-generating SGE technique using energy from salinity gradients. This research investigates the effect of membrane and feed characteristics on reverse electrodialysis (RED) power generation. Some investigations on the process parameters effect for the complement of the main study were also conducted. The generated power of RED was measured using power density analysis. The experiments were performed using artificial seawater varied from 0 to 1 g/L NaCl for diluted salt water and from 0 to 40 g/L NaCl for concentrated salt water. In a study of ions type, NaCl non-pa is used to represent monovalent ions, and MgSO4 represents divalent ions. The results showed that the highest voltage generation is 2.004 volts by 14 cells number of the RED membrane utilizing a RED self-made laboratory scale. The power density was enhanced by raising the flow rate (0.10 L/min), concentration difference (40 g/L), and the presence of electrode rinse solution. Further, the ion type (monovalent, divalent, and multivalent) influenced the resulting RED power density, where the divalent ion (MgSO4) 's power density was greater than that of the monovalent ion (NaCl). The resistance and selectivity of the membrane were the major keys for the power generation of RED

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Srivastava, Sunita, Anuj Chhabra, and Oleg Gang. "Effect of mono- and multi-valent ionic environments on the in-lattice nanoparticle-grafted single-stranded DNA." Soft Matter 18, no. 3 (2022): 526–34. http://dx.doi.org/10.1039/d1sm01171e.

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47

Wang, Jian, and Yi Fan Zhang. "The Study of Divalent Metal Ion Catalysts on Phenol-Formaldehyde Resol Resins." Applied Mechanics and Materials 71-78 (July 2011): 818–21. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.818.

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The curing characteristic of phenol-formaldehyde resol resins catalyzed with magnesium hydroxide, calcium hydroxide and barium hydroxide was studied in this study.The effects of catalysts on chemical structure of phenol formaldehyde resin was investigated by fourier transform infrared.The results indicated that divalent metal ions catalysts played an important role influence both the cure rate and cure time.Phenol formaldehyde resin catalysed by diffierent catalysts showed diffierent addition of formaldehyde onto ortho positions of phenolic rings.The order of the divalent metal ions effectiveness studied in alkaline conditions is calcium hydroxide, barium hydroxide and magnesium hydroxide.

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Nap, Rikkert J., Sung Hyun Park, and Igal Szleifer. "Competitive calcium ion binding to end-tethered weak polyelectrolytes." Soft Matter 14, no. 12 (2018): 2365–78. http://dx.doi.org/10.1039/c7sm02434g.

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We have developed a molecular model to describe the structural changes and potential collapse of weak polyelectrolyte layers end-tethered to planar surfaces and spherical nanoparticles as a function of pH and divalent ion concentration.

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49

Eldridge, Daniel S., Russell J. Crawford, and Ian H. Harding. "The role of metal ion-ligand interactions during divalent metal ion adsorption." Journal of Colloid and Interface Science 454 (September 2015): 20–26. http://dx.doi.org/10.1016/j.jcis.2015.04.056.

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50

Jin, Yee-Chung, and Songlin Ye. "Analytical solution for monovalent-divalent ion exchange transport in groundwater." Canadian Geotechnical Journal 36, no. 6 (December 1, 1999): 1197–201. http://dx.doi.org/10.1139/t99-064.

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An approximate analytical solution is derived for solute transport with monovalent-divalent ion exchange in saturated, steady, groundwater flow. The analytical solution is obtained by simplifying the complicated heterovalent ion exchange. Using a coordinate system that moves at the average solute advection velocity, a solution is obtained by direct integration with given boundary and initial conditions. The results agree well with a numerical solution using the original isotherm. The analytical solution presented is similar to that of monovalent-monovalent exchange, which suggests that a simple ion exchange model may be assumed for approximation.

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