Addition Of Sodium Ions Research Articles

Organogenèse induite chez des plants de Prosopis farcta (Fabaceae, Mimosoideae) développés in vitro par apport de diverses concentrations en ions Na+ et SO4 −-

The in vitro development of Prosopis farcta plants is dependent on the Na+ and SO4 −- ions concentration in culture medium. Different media were prepared by taking Gamborg medium, which macro elements were reduced by ten, as the basal medium and adding these ions at different concentrations. Medium containing low concentrations of sodium and sulphate, those added with Na+ in a concentration of 12.5 mM or 25 mM in the presence of a low concentration of SO4 −-, or with SO4 −- concentration of 25 mM in the presence of 0.1 mM of Na+ promoted the development of plants. The addition of Na+ at a low concentration with sulphate at 12.5 mM or the addition of sodium ions at 25 mM in the presence of 12.5 or 17 mM sulphate ion induced the formation of buds.

Selective Na+/K+ Effects on the Formation of α-Cyclodextrin Complexes with Aromatic Carboxylic Acids: Competition for the Guest

We investigated the effects of K(+) and Na(+) ions on the formation of α-cyclodextrin complexes with ionized aromatic carboxylic acids. Using solution calorimetry and (1)H NMR, we performed the thermodynamic and structural investigation of α-cyclodextrin complex formation with benzoic and nicotinic acids in different aqueous solutions containing K(+) and Na(+) ions as well as in pure water. The experiments show that the addition of sodium ions to solution leads to a decrease in the binding constants of the carboxylic acids with α-cyclodextrin as compared to pure water and solutions containing potassium ions. From another side, the effect of potassium ions on the binding constants is insignificant as compared to pure water solution. We suggest that the selectivity of cation pairing with carboxylates is the origin of the difference between the effects of sodium and potassium ions on complex formation. The strong counterion pairing between the sodium cation and the carboxylate group shifts the equilibrium toward dissociation of the binding complexes. In turn, the weak counterion pairing between the potassium cation and the carboxylate group has no effect on the complex formation. We complemented the experiments with molecular modeling, which shows the molecular scale details of the formation of cation pairs with the carboxylate groups of the carboxylic acids. The fully atomistic molecular simulations show that sodium ions mainly form direct contact pairs with the carboxylate group. At the same time, potassium ions practically do not form direct contact pairs with the carboxylate groups and usually stay in the second solvation shell of carboxylate groups. That confirms our hypotheses that the selective formation of ion pairs is the main cause of the difference in the observed effects of sodium and potassium salts on the guest-host complex formation of α-cyclodextrin with aromatic carboxylic acids. We propose a molecular mechanism explaining the effects of salts, based on competition between the cations and α-cyclodextrin for binding with the ionized carboxylic acids.

Evaluation of the sodium effect on the physicochemical properties of Mo/SnO2 catalysts

Abstract The effect of sodium addition on the physicochemical properties of Mo/SnO 2 catalysts was studied. The catalysts were prepared by precipitation using aqueous solution of ammonium heptamolybdate in two Mo amounts (5.5 and 14.5% (wt)); afterwards they were impregnated with sodium ion (1% wt). The solids were characterized by nitrogen adsorption, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, FTIR, and FTIR of adsorbed pyridine in order to evaluate changes on Mo species and textural and acidic properties. The results have shown that Mo/SnO 2 samples present dispersed isolated tetrahedral Mo species. The addition of sodium ion to Mo/SnO 2 catalysts promotes the transformation of dispersed isolated tetrahedral Mo species into dispersed two-dimensional polymolybdates and also causes changes in textural and acidic properties of these Mo/SnO 2 catalysts.

Determination of Sodium Ion Addition Sites of Peptides by Nanoelectrospray MS/MS Sequence Docking

Sodium ion addition of 20 naturally occurring amino acids was investigated by triple quadruple tandem mass spectrometry. Results showed that most amino acids had extraordinarily weak force for non-covalent binding to sodium ion, while proline and phenylalanine easily captured sodium ion from solvents. By tandem mass spectrometry “sequence docking” method on Q-TOF2 (Waters, USA), full amino acid sequence of C-terminal peptide of acidic fibroblast growth factor was analyzed and it was confirmed that the adding site of sodium ion was proline (6Pro). Sodium ion-addition peaks in peptide mass fingerprinting (PMF) apparently decreased after adding 1% formic acid. The peptide sequence without sodium ion-addition and the sequence gap were determined using de novo technology, which was the same as the sequence of sodium ion-addition peptide.

Investigation of Cooperativity in the Binding of Ligands to the D2Dopamine Receptor

The D(2) dopamine receptor exists as dimers or as higher-order oligomers, as determined from data from physical experiments. In this study, we sought evidence that this oligomerization leads to cooperativity by examining the binding of three radioligands ([(3)H]nemonapride, [(3)H]raclopride, and [(3)H]spiperone) to D(2) dopamine receptors expressed in membranes of Sf9 cells. In saturation binding experiments, the three radioligands exhibited different B(max) values, and the B(max) values could be altered by the addition of sodium ions to assays. Despite labeling different numbers of sites, the different ligands were able to achieve full inhibition in competition experiments. Some ligand pairs also exhibited complex inhibition curves in these experiments. In radioligand dissociation experiments, the rate of dissociation of [(3)H]nemonapride or [(3)H]spiperone depended on the sodium ion concentration but was independent of the competing ligand. Although some of the data in this study are consistent with the behavior of a cooperative oligomeric receptor, not all of the data are in agreement with this model. It may, therefore, be necessary to consider more complex models for the behavior of this receptor.

Optimisation of nickel extraction from laterite ores by high pressure acid leaching with addition of sodium sulphate

Extraction of nickel from Western Australian laterite ores via sulphuric acid leaching at 250 °C has been optimised by the addition of sodium sulphate. Leaching of a nontronitic nickel laterite ore in fresh water, with a sulphuric acid loading of 420 kg/t ore extracted 93% of nickel from the ore. When limonitic nickel laterite ore was leached in fresh water with an acid loading of 310 kg/t ore, 92% of the total nickel was extracted. The nickel extractions were optimised at 96% for the nontronitic ore and 95% for the limonitic ore, at the above acid loadings, when process water sodium ion levels were increased to 4 g/L and 2 g/L, respectively. Further addition of sodium ion resulted in a gradual decrease in overall nickel extraction, as the leach liquor free acidity decreased. At higher acid loadings, the process water sodium ion levels required for optimum extraction were also higher, so as to prevent dissolution of aluminium.

Sodium Application Enhances DDT Transformation in a Long-Term Contaminated Soil

Bioremediation is an economically attractive option to remediate soil contaminated with DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] and other organochlorine pesticides. However, lack of DDT bioavailability in soil presents one major obstacle to this technology particularly in soils that have been contaminated for long periods. In this work, sodium ion (Na+) was applied to a long-term DDT contaminated soil as Na+ is known to disperse clays, which would potentially release and/or expose physically protected DDT thereby enhancing DDT bioavailability. Sodium ion addition significantly increased dissolved organic carbon (DOC) levels, anaerobic bacterial numbers and the amount of DDT residues measured in soil solution. DDT transformation ranged from 95% (30—80 mg Na+ kg-1 soil) to 72% (no Na+ added) with the optimum level of DDT transformation occurring at 30 mg Na+ kg-1 soil. Higher Na+ levels repressed DDT transformation and this appeared to be related to lower DOC levels and flocculation of soils. The anaerobic incubation conditions employed (high water content) prevented DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] production and DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane] was the major breakdown product formed. Overall it appeared that Na+ has potential as a cheap and safe alternative to surfactants as a method for increasing DDT transformation in contaminated soil.

Enhancement of Li-ion battery performance of graphite anode by sodium ion as an electrolyte additive

Electrochemical performance of a graphite electrode for lithium-ion batteries was successfully and easily improved by sodium ion dissolved in an electrolyte solution. Sodium ion was added by dissolving 0.22 mol dm −3 NaClO 4 into a 1 mol dm −3 LiClO 4 ethylene carbonate–diethyl carbonate (1:1 by volume) electrolyte solution prior to charge–discharge cycle. By sodium-ion addition, an irreversible capacity at the initial cycle was obviously reduced, and reversible discharge capacities increased with better capacity retention. From ac impedance measurements, a graphite electrode in the sodium ion added electrolyte had much smaller interface resistance compared to that obtained in sodium ion free one. Furthermore, the electrode surface morphology observed by electron microscopes after charge–discharge tests got more uniform in the sodium added electrolyte.

Extraction of rare earth metals by calix[4]arene solubilized in AOT reversed micellar solution

Abstract Extraction of rare earth metals (europium and yttrium) and their separation from zinc were investigated using a novel host compound, p - tert -octylcalix[4]arene carboxyl derivative as an extractant. Extraction behavior of the metals with a typical commercial extractant PC-88A or Versatic 10 was also examined. The cyclic ligand calixarene showed a high selectivity towards rare earth metals compared with PC-88A and Versatic 10. The addition of sodium ion into the feed aqueous solution enhanced the extractability of rare earth metals, and resultantly, improved the selectivity. The drawback of this promising extractant was the poor solubility in organic solvents, especially in nontoxic aliphatic solvents such as isooctane and kerosene. We attempted to solubilize the novel extractant calix[4]arene in isooctane by utilizing reversed micelles formed with an anionic surfactant AOT. p - tert -Butylcalix[4]arene could be dissolved in the AOT–isooctane reversed micellar solution by injecting an adequate amount of water. Furthermore, the extraction of metals from the aqueous solution dissolving sodium ion was conducted by the AOT–isooctane system containing p - tert -butylcalix[4]arene. The excellent extraction and separation of metals was achieved by using calixarene solubilized in the AOT-reversed micellar solution.

Allosteric modulation of A 2A adenosine receptors by amiloride analogues and sodium ions

Allosteric regulation of rat A 2A adenosine receptors by amiloride, amiloride analogues, and sodium ions was studied by investigating their ability to influence the dissociation of [ 3H]4-{2-[7-amino-2-(2-furyl)-1,2,4-triazolo[1,5- a][1,3,5]triazin-5-yl-amino]ethyl}phenol ([ 3H]ZM241385) from receptors in rat striatal membranes. Both amiloride and its analogues accelerated the dissociation, the analogues being more potent than amiloride itself. In contrast, sodium ions decreased the rate of [ 3H]ZM241385 dissociation in a concentration-dependent manner, and this rate was not influenced by guanosine triphosphate, N-ethylmaleimide, suramin, or the selective A 2A adenosine receptor antagonist, 5-amino-2-(2-furyl)-7(2-phenylethyl)pyrazolo[4,3- e]-1,2,4-triazolo[1,5- c]pyrimidine (SCH58261). The effect of competition between the amiloride analogue 5-( N, N-hexamethylene)amiloride (HMA) and sodium ions on [ 3H]ZM241385 dissociation was also explored. The addition of sodium ions resulted in a concentration-dependent rightward shift of the HMA response curve. The slopes of the HMA concentration–response curves in the presence and absence of sodium ions were not significantly different, which suggests that sodium ions and amiloride analogues act at a common allosteric site on the A 2A adenosine receptor. There was a lack of correlation between the displacement of ligand binding and the allosteric potencies of the amiloride analogues.

Improving the throwing power of nickel electroplating baths

The throwing power of nickel electroplating baths was measured from the extent of plating penetration inside a tube by applying a new formula which relates the degree of penetration to the crevice dimensions and plating current. The effect of different factors such as pH value, anion or cation additives on the throwing power of different composition baths were investigated. The throwing power was shown to improve with the increase of pH value and the addition of sodium ions in the form of chloride, borate or hypophosphite salts. High values of throwing power of nickel baths were achieved in hypophosphite, chloride, sulphate and borate baths.

Effect of sodium ions on the extraction of rare earth metals by liquid surfactant membranes containing a calix[4]arene carboxyl derivative

A novel host compound calixarene has been applied as a mobile carrier for the separation and concentration of rare earth metals by liquid surfactant membranes (LSMs). Using the novel carrier, extraction of rare earth metals (Ho, Er and Y) by LSMs was systematically studied in a stirred cell. Extraction behavior of rare earth metals by the carboxyl derivative of calix[4]arene was found to be extremely sensitive to coexisting sodium ions in the feed solution. The extractability of rare earth metals was remarkably enhanced by the addition of sodium ions. The permeation rate of rare earth metals through the LSMs in the presence of sodium ions was 100-fold higher than that without sodium ions. This enhancement of the permeation rate is attributed to the preferential conformation change in the host compound of calixarene initiated by sodium ions. The permeation mechanism of rare earth metals by LSMs is elucidated by an interfacial reaction model.

Rare Earth Metal Extraction by Liquid Surfactant Membranes Containing a Calixarene Carboxylate Derivative: Permeation Acceleration Effect of Sodium Ions

ABSTRACT Calixarene carboxylate derivatives were used as a mobile carrier for rare earth permeation in a liquid surfactant membrane (LSM) system. The effect of alkali metal ions on the extraction behavior of rare earth metals in both liquid-liquid extraction and LSM systems has been studied. The addition of sodium ions considerably enhanced the extraction ability of rare earth metals in the extraction equilibrium. Furthermore, the presence of alkali metal ions in the material solution affected the rate of rare earth permeation in LSMs. The most accelerative transport of rare earth metals by LSMs was achieved by the addition of sodium ions. This acceleration effect of sodium ions was predominant in a tetracarboxylate calixarene whose cavity size just fits the ionic diameter of sodium ions. The sodium-loaded calix[4]arene derivative showed good performance as an effective mobile carrier for rare earth metals in the presence of sodium ions.

The evaluation of crown ether based niosomes as cation containing and cation sensitive drug delivery systems

A novel crown ether amphiphile N-hexadecanoyl-2-aminomethyl-15-crown-5 (PCE) has been synthesised from hexadecanoic acid N-hydroxysuccinimide ester and 2-aminomethyl-15-crown-5, with the aim of developing a cation containing or cation sensitive controlled release system. Niosomes were prepared with a 1:1 molar ratio of PCE and cholesterol (CHOL) with and without the addition of 10 mol% Solulan C24 (poly-24-oxyethylene cholesteryl ether). A water-soluble fluorescent marker, rhodamine B was encapsulated within these niosomes. Rhodamine B containing PCE/CHOL niosomes of approximately 6.3 μm diameter were visualised by optical microscopy and sonicated PCE/CHOL niosomes of approximately 134 nm in size were visualised by transmission electron microscopy. The release of the fluorescent marker rhodamine B from PCE/CHOL niosomes was slightly increased by the addition of calcium ions but remained unaffected by the addition of sodium ions. This is thought to be due to a slightly greater ease of divalent cation chelation by the crown ether head groups when compared to the monovalent cation, the latter of which are more highly solvated in aqueous solution. This is the first study on the effect of ions on the release properties of crown ether based niosomes. These systems may be developed as cation containing or cation sensitive release systems for drug delivery and other industrial uses.

Model Pumices Supported Metal Catalysts

The catalyzed, selective hydrogenation, in liquid phase, of 1,3-cyclooctadiene was studied on a series of Pd catalysts supported on natural pumice, model pumices (with variable content of alkali metal ions), silica, and sodium-doped silica. At constant pressure of H2(1 atm.) the reaction follows a zero-order kinetic for all the Pd catalysts. At low metal dispersion (Dx<20%), Pd/pumice catalysts exhibit higher activity as compared to Pd/silica catalysts; the turnover frequency is maintained even at high metal dispersion in Pd/pumice but Pd/silica and Pd/model pumices without alkali ions show a decrease in activity. At increasingDx, the binding energy shift of Pd 3dlevel is negative in Pd/pumice and positive in Pd/silica with respect to unsupported Pd metal. The different performances of the Pd/pumice catalysts are explained by the presence of alkali metal ions in the framework of the support. Addition of sodium ions to Pd/silica catalysts produces a negative shift of the binding energy, but the activity is not improved because the number of active sites diminished due to decoration of palladium particles by sodium ions. The Pd catalysts with alkali metal ions in the support are resistant to air oxidation. In Pd catalysts containing alkali metal ions the selectivity to cyclooctene is practically 100% and the constant rates ratiok1/k2is more than 1000 with a maximum at dispersion 35–40%, whereas the selectivity in Pd catalysts without alkali metal ions decreases continuously at increasing dispersion.

Localization of Alkali Metal Ions in Sodium-Promoted Palladium Catalysts as Studied by Low Energy Ion Scattering and Transmission Electron Microscopy

Three series of palladium-based catalysts have been studied by Low Energy Ion Scattering (LEIS) and Transmission Electron Microscopy (TEM). The first series is comprised of Na–Pd/SiO2catalysts, obtained by addition of palladium to a silica support and by further addition of sodium ions with a Na/Pd atomic ratio (R) equal to 0, 6.4, and 25.6. The second series consists of palladium catalysts supported on natural pumice, in which, due to a different loading of supported palladium,R′, the (Na+K)/Pd atomic ratio, is equal to 17.0 and 39.4. The third series is represented by two palladium-based catalysts supported on “model pumices,” synthetic silico-aluminates, obtained by sol-gel techniques, with a different amount of sodium, andRequal to 2.1 and 6.1, respectively. LEIS experiments and electron microscopy demonstrate a different location of alkali metal ions in the first two series: in the Na–Pd/SiO2catalysts sodium is distributed in a way which is not uniform on the support and on the palladium metal, which is partly decorated with Na ions, whereas in the Pd/natural-pumice series the palladium surface is sodium-free. The results on the third series of catalysts, Pd/model pumice, are not definitive on the basis of the LEIS and TEM analyses, but by FTIR study of CO and CO2adsorption, the decoration of palladium by sodium ions could be excluded. The results confirm the importance of the alkali metal ion location in alkali-promoted palladium catalysts and open new possibilities in the design of palladium-supported catalysts by a better control of promoter location.

CARRAGEENAN MEDIATED CLARIFICATION OF DIALYSED WORT SYSTEMS

Fining trials with kappa-carrageenan in dialysed wort demonstrated that potassium or calcium cations were essential for the flocculation of non-microbiological particulate material. The relative ability of metal cations to promote flocculation followed identical trends as established for carrageenan helix stabilising action and gelation (K+ > Ca2+ > Na+). Carrageenan also exhibited interaction with soluble wort polypeptides, in particular fractions of relative molecular mass (Mr) 70 000 and 40 000. This interaction occurred in the absence of added metal cations and was suppressed by increasing concentrations of potassium or calcium. Addition of sodium ions to systems containing potassium had no effect on either interaction with soluble polypeptides or the flocculation of particulate material. Decreasing the pH of dialysed wort impaired flocculation reactions but enhanced removal of soluble wort polypeptides. These results suggest that reaction between carrageenan and soluble polypeptides occurs via electrostatic interactions whereas flocculation of particulate material requires the presence of carrageenan in a helical conformation.

Classification of Opioid Agonists and Antagonists Based on Receptor Occupancy in the Brain.

In order to classify opioid agonists and antagonists based on the receptor occupancy in the brain, the information on the therapeutic plasma concentration of these drugs and the binding affinity to μ opioid receptor was collected. The analysis was performed on eight opioid agonists (morphine, sufentanil, fentanyl, methadone, pethidine, levorphanol, buprenorphine and pentazocine) and two antagonists (naltrexon and naloxon) obtained data on the plasma concentration after therapeutic dosing, the plasma unbound fraction and dissociation constant (Kd) of the brain receptor binding. The mean plasma concentration and unbound plasma concentration varied 4000 and 10000 fold among the opioid agonists, respectively. Moreover, no difference in the plasma concentration or unbound plasma concentration was observed between the agonists and antagonists. On the other hand, the binding occupancy of the agonists to receptor (ranged 1.4-25.0%) calculated using the value of Kd with addition of sodium ions and therapeutic concentration of unbound drug was substantially smaller than that of the agonists (57.1-96.0%), although no difference in the binding occupancy calculated using the Kd without addition of sodium ions was observed between the agonists (ranged 1.8-89.0%) and antagonists (57.1-96.0%). From these results, the receptor occupancy of opioid calculated using the value of Kd with addition of sodium ions may be more useful index for the classification of opioid agonists and antagonists.

Formation of a functionally active sodium-translocating hybrid F1F0 ATPase in Escherichia coli by homologous recombination.

A deletion mutant of Escherichia coli lacking the genes for ATPase subunits a, c, b, delta and part of the alpha subunit was transformed with a plasmid containing the corresponding genes of the sodium-translocating ATPase of Propionigenium modestum. The respective DNA fragment of P. modestum was integrated into the genome of the E. coli deletion mutant by site-specific homologous recombination. The sites of this recombination event were identified by cloning and DNA sequencing. As a consequence of the recombination event, a functionally active hybrid ATPase was obtained by in vivo complementation. The biochemical characterization of this hybrid ATPase revealed high sensitivity to dicyclohexylcarbodiimide as well as strong activation by the addition of sodium ions. After reconstitution into liposomes, the hybrid ATPase catalysed the transport of Na+ upon ATP addition. In the absence of Na+, the ATPase hybrid was able to pump protons, as was shown by the ATP-dependent fluorescence quenching of 9-amino-6-chloro-2-methoxyacridine.

Structure Elucidation of Furostanol Glycosides Using Liquid Secondary Ion Mass Spectrometry

The structures of five genuine furostanol glycosides isolated from Metanarthecium luteo-viride MAXIM. (Liliaceae) were determined on the basis of liquid secondary ion mass spectrometric (LSIMS) analysis including liquid secondary ion mass spectrometry/mass spectrometry (LSIMS/MS). These glycosides were elucidated as bisdesmosides of furostanols (i.e. 2-0-acetyl-furometagenin, furometagenin, furonogiragenin, 2-0-acetyl- furometanarthogenin and 2-O-acetyl-3-oxo-furometagenin) as aglycons. which have cyclic hemiacetal moieties. bearing 2,3,4-tri-O-acetyl arabinopyranose at 11−C 1) and glucopyranose at 26-C. In the LSIMS of these compounds, the protonated molecular ion [M + H] + was not observed but the fragment ion [M - OH] + corresponding to the loss of the hydroxyl group at 22-C was observed. By addition of NaCI to the sample matrix, the ion peaks for [M + Na] + appeared in the spectra, which were used to determine the molecular formulae. Molecular orbital calculation of a model compound indicated that the ions [M+Na] + were stabilized by formation of a four-membered ring structure bonding two oxygen atoms at the hemiacetal moiety and a sodium ion. Since the energy required for sodium ion addition to the neutral molecule was less than for proton addition, the sodium ion addition is more favorable. In addition, the repulsion energy of the protonated hemiacetal hydroxyl group is only 4.25 kcal/mol, and the potential energy of the fragmentation products ([M - OH] + + H 2 0) is 18.13 kcal/mol less than that of [M + H] +. These data rationalized the easy dehydration from the protonated furostanol glycoside.