High Concentrations Of Sodium Ions Research Articles

Recovery of precious metals from ammoniacal thiosulfate solutions by hybrid mesoporous silica: 1-Factors affecting gold adsorption

Mesoporous silica materials mainly of type MSU-X functionalized with simple amine and thiol (mercapto-) ligands, have been used to adsorb gold thiosulfate complex from ammoniacal copper-bearing solutions. Variation in major reagent concentrations was investigated for the determination of the appropriate dosages of ammonium, thiosulfate and cupric salts to obtain a high recovery of gold thiosulfate from simulated leach solutions. It was found that ammonium/ammonia concentration and specifically its ratio with respect to that of thiosulfate had determining effects on gold adsorption by functionalized mesoporous silica. The adsorbents performed well in both neutral and alkaline pH provided that the latter was provided by aqueous ammonia solution. There was significant interference with gold adsorption in presence of high concentrations of sodium ions in the solutions. Among the anionic species, chloride was found to cause the largest detrimental effect on gold thiosulfate uptake by the hybrid silica. Adsorption isotherms and kinetics of gold recovery by functional mesoporous silica were investigated. The material showed exceptionally high adsorption capacities reaching above 3mmol (∼600mg) gold per gram of amine-bearing adsorbent accompanied by an average maximum of 80% precious metal recovery.

New Technologies for Decontamination of Radioactive Substances Scattered by Nuclear Accident / Nowe Technologie Dekontaminacji Radioaktywnych Substancji Rozproszonych Przez Awarie Nuklearna

Our effort for decontamination of radioactive cesium scattered widely by nuclear accident in March 2011 in Fukushima, Japan has been described. Radioactive cesium scattered widely in Japan has been accumulating in arc or plasma molten-solidified ash in waste incinerating facilities up to 90,000 Bq/kg of the radioactive waste. Water rinsing of the ash resulted in dissolution of cesium ions together with high concentrations of potassium and sodium ions. Although potassium inhibits the adsorption of cesium on zeolite, we succeeded to precipitate cesium by in-situ formation of ferric ferrocyanide and iron rust in the radioactive filtrate after rinsing of the radioactive ash with water. Because the regulation of no preservation of any kind of cyanide substances, cesium was separated from the precipitate consisting of cesium-captured ferric ferrocyanide and ferric hydroxide in diluted NaOH solution and subsequent filtration gave rise to the potassium-free radioactive filtrate. Cesium was captured by zeolite from the potassium-free radioactive filtrate. The amount of this final radioactive waste of zeolite was significantly lower than that of the arc-molten-solidified ash.

Development of poly(butylene succinate) microspheres for delivery of levodopa in the treatment of Parkinson's disease

Parkinson's is a major neurodegenerative disorder that occurs due to loss of dopaminergic neurons in basal ganglia. Conventional therapy includes surgery that involves lot of risk and administration of levodopa which is accompanied by poor bioavailability, short half-life, and side effects. In the present study, poly(butylene succinate) (PBSu) microspheres-based drug delivery system to improve the bioavailability of the drug levodopa was evaluated for the first time. Biodegradable porous and smooth PBSu microspheres were prepared by double emulsion solvent evaporation technique (W/O/W) and the effect of solvent and surfactant was studied. The maximum encapsulation efficiency achieved was 53.93% and 62.28% for porous and smooth microspheres, respectively. In vitro drug release was studied in phosphate buffered saline and simulated CSF buffer of pH 7.4. Initially a burst effect followed by sustained release of drug was obtained for about 32 h and 159 h for porous and smooth microspheres, respectively. The release rate was higher in simulated CSF when compared with PBS, due to higher concentration of sodium ions and cations in simulated CSF.

Pulp mill wastewater sediment reveals novel methanogenic and cellulolytic populations

Pulp mill wastewater generated from wheat straw is characterized as high alkalinity and very high COD pollution load. A naturally developed microbial community in a pulp mill wastewater storage pool that had been disused were investigated in this study. Owing to natural evaporation and a huge amount of lignocellulose's deposition, the wastewater sediment contains high concentrations of organic matters and sodium ions, but low concentrations of chloride and carbonate. The microbiota inhabiting especially anaerobic community, including methanogenic arhcaea and cellulolytic species, was studied. All archaeal sequences fall into 2 clusters of family Halobacteriaceae and methanogenic archaeon in the phylum Euryarchaeota. In the methanogenic community, phylogenetic analysis of methyl coenzyme M reductase A (mcrA) genes targeted to novel species in genus Methanoculleus or novel genus of order Methanomicrobiales. The predominance of Methanomicrobiales suggests that methanogenesis in this system might be driven by the hydrogenotrophic pathway. As the important primary fermenter for methane production, the cellulolytic community of enzyme GHF48 was found to be dominated by narrower breadth of novel clostridial cellulase genes. Novel anoxic functional members in such extreme sediment provide the possibility of enhancing the efficiency of anoxic treatment of saline and alkaline wastewaters, as well as benefiting to the biomass transformation and biofuel production processes.

Effects of Monovalent Cations on the Competitive Adsorption of Perfluoroalkyl Acids by Kaolinite: Experimental Studies and Modeling

Our hypothesis that longer-chained perfluoroalkyl acids (PFAAs) outcompete shorter-chained PFAAs during adsorption was tested in this study, wherein the adsorption interactions of six frequently detected PFAAs with kaolinite clay were modeled and examined experimentally using various suspension compositions. Competitive adsorption of PFAAs on the kaolinite surface was observed for the first time, and longer-chained PFAAs outcompeted those with a shorter chain. The electrostatic repulsion between adsorbed PFAA molecules is a primary inhibitory factor in PFAA adsorption. An increase in aqueous sodium or hydrogen ion concentration weakened electrostatic repulsions and changed the adsorption free energy. Therefore, the adsorption of a shorter-chained PFAA with weaker hydrophobicity could occur at high sodium or hydrogen ion concentrations. The experimental and modeling data suggest that the adsorption of shorter-chained PFAAs (≤4 perfluorinated carbons) in freshwater with a typical ionic strength of 10(-2.5) is not thermodynamically favorable. Furthermore, by measuring the electrokinetic potential of kaolinite suspension in the presence of PFAAs, we found that the kaolinite surface became more negatively charged because of the adsorption of PFAAs. This observation indicates that the adsorbed PFAA molecules were within the electrical double layer of the kaolinite surface and that they contributed to the potential at the slipping plane. The possible alignments of adsorbed PFAA molecules on the kaolinite surface were then proposed.

Ammonia stripping for enhanced biomethanization of piggery wastewater

In this study, the effects of ammonia removal by air stripping as a pretreatment on the anaerobic digestion of piggery wastewater were investigated. Ammonia stripping results indicated that ammonia removal was strongly dependent on pH and aeration rate, and the ammonia removal rate followed the pseudo-first-order kinetics. A significant enhancement of biomethanization was observed for wastewaters of which ammonia was air-stripped at pH 9.5 and pH 10.0. The methane productivity increased from 0.23 ± 0.08 L CH 4/L d of the control (raw piggery wastewater) to 0.75 ± 0.11 L CH 4/L d (ammonia-stripped at pH 9.5) and 0.57 ± 0.04 L CH 4/L d (ammonia-stripped at pH 10.0). However, the improvement of methane production from the piggery wastewater pretreated at pH 11.0 was negligible compared to the control, which was thought to be due to the high concentration of sodium ions supplied from sodium hydroxide for pH adjustment. From these results, it was concluded that ammonia removal through air stripping at the alkaline pH could be a viable option for preventing the failure of anaerobic digestion of the raw piggery wastewater. Additionally, it was also found that a high concentration of sodium ion originated from sodium hydroxide for pH adjustment inhibited methane production.

Simple and sensitive fluorescence sensor for detection of potassium ion in the presence of high concentration of sodium ion using berberine–G-quadruplex complex as sensing element

In this work, a novel potassium ion (K+) sensor is presented using berberine–G-quadruplex complex as a fluorescent probe. This sensor is based on the K+that can induce the G-rich DNA to form G-quadruplex conformation. The G-quadruplex can bind berberine to form berberine–G-quadruplex complex, resulting in remarkable enhancement of fluorescence emission of the berberine–G-quadruplex system. In the presence of 800mM sodium ion (Na+), the fluorescence of the berberine–G-quadruplex complex increased linearly with increasing K+ concentration in the range of 0.005–1.0mM. The turn-on fluorescent assay is simple, inexpensive, and highly sensitive. We observed that Na+ in 10,000-fold molar excess does not interfere. The molecular mechanisms which produce enhanced fluorescence of berberine were discussed.

Similarities in functional attributes and nutritional effects of magadi soda and bean debris-ash used in cooking African traditional dishes

Magadi soda and bean debris-ash have been used as condiments for a long time by various ethnic groups in East and Central Africa in cooking traditional dishes. The aim of the study was to investigate whether magadi soda and bean debris-ash had similar effects and functional attributes when added to traditional dishes during cooking. Reason for the addition of the two condiments has not been revealed by researchers. Mineral content, in-vitro bioavailability studies and pH of non-ashed and ashed magadi soda and bean debris were evaluated. The results indicated that high concentrations of sodium ions (30.2%) and potassium ions (64.2%) were observed in magadi soda and bean debris-ash, respectively. In-vitro iron and zinc bioavailability decreased significantly with the addition of magadi soda and bean debris-ash in maize, beans and sorghum. Equally, the cooking time was significantly reduced. The mean pH for both magadi soda (9.66) and bean debris-ash (9.75) were not significantly different indicating that both aqueous solutions had alkaline properties. The similarity in properties especially in mineral profile, alkalinity, decreased cooking time and lowered mineral uptake by magadi soda and bean debris-ash explain similar functionality in foods they are added to during cooking. Despite the similarities observed, communities should be informed of the negative nutritional effects of these condiments so as to diversify their meal patterns accordingly. Key words : Magadi soda, bean ash, traditional dishes, minerals, in-vitro bioavailability

The effects of sodium in ITO by pulsed laser deposition on organic light-emitting diodes

The depth profile of ITO on glass was measured by the time-of-flight secondary ion mass spectroscopy (TOFSIMS) which revealed high sodium (Na) ion concentration at the ITO surface as well as at the ITO–glass interface as a result of out diffusion with substrate heating. Effects of Na ions on the performance of organic light-emitting diode (OLED) were studied by etching away a few tens of nanometers off the ITO surface with a dilute aquaregia solution of HNO3:HCl:H2O. A single-layer, molecularly doped ITO/(PVK+TPD+Alq3)/Al OLEDs were fabricated on bare and etched ITO samples. Although the removal of a 10-nm layer of ITO surface increased the voltage range, brightness, and lifetime, it was insufficient to correlate these improvements with solely to the Na ion reduction without considering the surface roughness.

Insight into the strong inhibitory action of salt on activity of neocarzinostatin

Enediyne anticancer drugs belong to one of the most potent category in inducing DNA damage. We report 85 ± 5% inhibition on activity of neocarzinostatin by salt. As high sodium ion concentration is a known tumor cell feature, we explored the dynamic mechanism of inhibition. Using various analytical tools, we examined parameters involved in the four consecutive steps of the drug action, namely, drug releasing from carrier protein, drug–DNA binding, drug activating, and DNA damaging. Neither protein stability, nor drug release rate, was altered by salt. The salt inhibition level was similar in between the protein-bound and unbound enediyne chromophore. Salt did not quench the thiol-induced drug activation. The inhibition was independent of DNA lesion types and irrelevant with thiol structures. Collectively, no salt interaction was found in the releasing, activating, and DNA damaging step of the drug action. However, binding with DNA decreased linearly with salt and corresponded well with the salt-induced inhibition on the drug activity. Salt interference on the affinity of DNA binding was the main and sole cause of the severe salt inhibition. The inhibition factor should be carefully considered for all agents with similar DNA binding mode.

Strategies of pH control and glucose‐fed batch fermentation for production of succinic acid by Actinobacillus succinogenes CGMCC1593

AbstractBACKGROUND: Succinic acid is an important precursor of numerous products, including pharmaceuticals, feed additives, green solvents, and biodegradable polymers. In this work, strategies of pH control and glucose‐fed batch fermentation for producing succinic acid using Actinobacillus succinogenes CGMCC1593 were carefully optimized.RESULTS: The production of succinic acid was stable within the pH range 6.0–7.2. Both cell growth and succinic acid production were inhibited by high concentrations of sodium and calcium ions, while there was no significant inhibition by magnesium ions. With an initial glucose concentration of 25 g L−1, and glucose concentration was maintained between 10 and 15 g L−1 during the course of fed batch fermentation, succinic acid concentration, productivity and yield were 60.2 g L−1, 1.3 g L−1 h−1 and 75.1%, respectively.CONCLUSION: Of all the neutralization reagents used for pH control of A. succinogenes CGMCC1593, solid MgCO3 was the most satisfactory. With increase of initial glucose concentration, the time course showed a longer growth lag period and the maximum biomass declined, while more carbon was diverted to succinate synthesis. The results obtained in this study should be helpful for the design of a highly efficient succinic acid production process. Copyright © 2008 Society of Chemical Industry

Cytokines in human breast cyst fluid

Gross cystic breast disease is a common benign disorder in which palpable cysts occur in the breast and are normally treated by aspiration of the contents. The cysts are classified as either Type 1, containing a high level of potassium ions and a low level of sodium ions, or as Type 2, with low potassium and high sodium ion concentrations. Steroid sulphatase activity in MDA-MB-231 and MCF-7 cell lines is regulated by exogenous breast cyst fluid (BCF), possibly because of cytokines in the BCF. A screening method was used to determine the range of cytokines in eight BCFs, four of each type. This was an array system, which uses antibodies immobilised on a membrane to qualitatively detect 79 different cytokines or growth factors. Nine cytokines were detected well above background levels: all were found in both types of BCF, but only epidermal growth factor (EGF) was higher in Type 1. All the other factors were higher in Type 2 BCF. Two of these cytokines, IL-6 and EGF, have previously been suggested to affect steroid sulphatase expression and several (MIP-1β, IL-8, NAP-2) are known to affect MCF-7 cell chemotaxis. In addition two cytokines were measured by ELISA in 57 BCFs, and both IL-1β and IL-13 were found in BCF, with significantly higher amounts of IL-1β in Type 1 than Type 2 BCF (35.5 ± 4.4 pg/ml versus 9.9 ± 2.9 pg/ml).

Electrochemistry of Graphite in Li and Na Salt Codissolving Electrolyte for Rechargeable Batteries

Electrochemical reduction and oxidation of a graphite electrode were carried out in nonaqueous electrolytes that consisted of ethylene carbonate/diethyl carbonate (1:1) solvents where and were codissolved. Reversible lithium intercalation into graphite occurred accompanied with no remarkable side reactions in the potential range between 1.5 and vs , that is, no sodium deposition and no sodium intercalation were observed. Comparing to results in a sodium-free electrolyte, i.e., a conventional electrolyte in Li-ion batteries, the initial irreversibility was noticeably suppressed by codissolving sodium ions, and kinetics of the lithium intercalation were enhanced with better capacity retention during cycling. Additionally, the redox behavior of graphite for lithium-ion batteries was improved by sodium ion coexistence, with no inferior influences on the negative and positive electrodes and electrolyte. When the sodium ion concentration increased to , the superior reversibility of lithium intercalation was observed in comparison with that in a sodium-free system; however, the higher concentration of sodium ions deteriorated the lithium intercalation properties. We found that a surface layer formed on graphite electrode got less resistive as a lithium-ion conductor by entrapping sodium during the initial electroreduction with optimal concentration.

Modulating drug release and matrix erosion of alginate matrix capsules by microenvironmental interaction with calcium ion

Effect of calcium gluconate (CG) content on release of dextromethorphan hydrobromide (DMP), model drug, from capsules containing low and medium viscosity grades of sodium alginate (SA) was investigated in different dissolution media. Matrix erosion of the SA matrix capsules in distilled water and pH 7.4 phosphate buffer was compared. Molecular interaction of SA with calcium ion in surface gel layer of the SA matrix capsules was examined using Fourier transform infrared spectroscopy and differential scanning calorimetry. In distilled water and pH 7.4 phosphate buffer, DMP release rate depended on the viscosity grade of SA, whereas a comparable DMP release rate was found in 0.1 N HCl. Incorporation of CG into the SA matrix capsules caused a faster drug release in acidic medium because CG acted as a channeling agent in the hydrated insoluble gel matrix of alginic acid. Interaction of calcium ions with carboxyl groups of SA could be formed in surface gel layer of hydrated matrix capsules in distilled water. This led to a more rigid matrix gel structure that caused a slower drug release and matrix erosion. In contrast, the extent of this interaction in pH 7.4 phosphate buffer was less than that in distilled water because the common ion effect and high concentration of sodium ion retarded the hydration of SA and the binding of calcium ions with carboxyl groups of SA. Thus, a small change in drug release and matrix erosion was observed. This finding suggests that microenvironmental interaction between hydrated SA and calcium ion in distilled water could be created in the formulations prepared using low compression force. Moreover, incorporation of CG could moderate drug release and matrix erosion of the SA matrix capsules.

ADP-ribosyltransferase-specific Modification of Human Neutrophil Peptide-1

Epithelial cells lining human airways and cells recruited to airways participate in the innate immune response in part by releasing human neutrophil peptides (HNP). Arginine-specific ADP-ribosyltransferases (ART) on the surface of these cells can catalyze the transfer of ADP-ribose from NAD to proteins. We reported that ART1, a mammalian ADP-ribosyltransferase, present in epithelial cells lining the human airway, modified HNP-1, altering its function. ADP-ribosylated HNP-1 was identified in bronchoalveolar lavage fluid (BALF) from patients with asthma, idiopathic pulmonary fibrosis, or a history of smoking (and having two common polymorphic forms of ART1 that differ in activity), but not in normal volunteers or patients with lymphangioleiomyomatosis. Modified HNP-1 was not found in the sputum of cystic fibrosis patients or in leukocyte granules of normal volunteers. The finding of ADP-ribosyl-HNP-1 in BALF but not in leukocyte granules suggests that the modification occurred in the airway. Most of the HNP-1 in the BALF from individuals with a history of smoking was, in fact, mono- or di-ADP-ribosylated. ART1 synthesized in Escherichia coli, glycosylphosphatidylinositol-anchored ART1 released with phosphatidylinositol-specific phospholipase C from transfected NMU cells, or ART1 expressed endogenously on C2C12 myotubes modified arginine 14 on HNP-1 with a secondary site on arginine 24. ADP-ribosylation of HNP-1 by ART1 was substantially greater than that by ART3, ART4, ART5, Pseudomonas aeruginosa exoenzyme S, or cholera toxin A subunit. Mouse ART2, which is an NAD:arginine ADP-ribosyltransferase, was able to modify HNP-1, but to a lesser extent than ART1. Although HNP-1 was not modified to a significant degree by ART5, it inhibited ART5 as well as ART1 activities. Human beta-defensin-1 (HBD1) was a poor transferase substrate. Reduction of the cysteine-rich defensins enhanced their ability to serve as ADP-ribose acceptors. We conclude that ADP-ribosylation of HNP-1 appears to be primarily an activity of ART1 and occurs in inflammatory conditions and disease.

Comparison of Microenvironments of Aqueous Sodium Dodecyl Sulfate Micelles in the Presence of Inorganic and Organic Salts: A Time-Resolved Fluorescence Anisotropy Approach

Microenvironments of aqueous sodium dodecyl sulfate (SDS) micelles was examined in the presence of additives such as sodium chloride and p-toluidine hydrochloride (PTHC) by monitoring the fluorescence anisotropy decays of two hydrophobic probes, 2,5-dimethyl-1,4-dioxo-3,6-diphenylpyrrolo[3,4-c]pyrrole (DMDPP) and coumarin 6 (C6). It has been well-established that SDS micelles undergo a sphere-to-rod transition and that their mean hydrodynamic radius increases from 19 to 100 A upon the addition of 0.0-0.7 M NaCl at 298 K. A similar size and shape transition is induced by PTHC at concentrations that are 20 times lower compared to that of NaCl. This study was undertaken to find out how the microviscosity of the micelles is influenced under these circumstances. It was noticed that the microviscosity of the SDS/NaCl system increased by approximately 45%, whereas there was a less than 10% variation in the microviscosity of the SDS/PTHC system. The large increase in the microviscosity of the former system with salt concentration has been rationalized on the basis of the high concentration of sodium ions in the headgroup region of the micelles and their ability to strongly coordinate with the water present in this region, which decreases the mobility of the probe molecules.

Novel mesoporous organosilicas containing size-selective micropores from covalently bound calixcrowns

Novel mesoporous organosilicas containing size-selective micropores from covalently bound calix[4]arenecrown-6s (calixcrowns) have been synthesized. Microporous calixcrowns, which are selective for caesium ions, were bonded covalently to triethoxysilyl groups via hydrosilylation. Co-polymerization of the silylated calixcrown monomer with tetraethoxysilane in the presence of a structure-directing surfactant, cetyltrimethylammonium bromide (CTAB), resulted in the formation of organosilicas containing calixcrown-based size-selective micropores. Removal of the surfactants produced organosilicas containing both mesoporous matrix cavities and microporous calixcrown host cavities. The solid-state 13C and 29Si spectra provided evidence for intact covalently attached calixcrown hosts. The mesoporosity of the surfactant-extracted calixcrown-containing organosilicas was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen porosimetry. Experiments on the extraction of caesium ions from water in the presence of high concentrations of sodium ions by the insoluble calixcrown-containing mesoporous organosilicas showed good uptake and high caesium selectivity by these novel materials. Simple filtration removes the material containing the extracted caesium ions.

Novel polymeric chelating fibers for selective removal of mercury and cesium from water.

We report here the synthesis and characterization of two new classes of chelating fibers, namely, (1) polymercaptopropylsilsesquioxane (PMPS) and (2) copper(II) ferrocyanide complexed with poly[1-(2-aminoethyl)-3-aminopropyl]silsesquioxane (Cu-FC-PAEAPS) fibers. These fibers were evaluated for selective removal of trace amount of mercury and cesium ions respectively in the presence of competing metal ions from water. The PMPS and Cu-FC-PAEAPS fibers were prepared by coating their corresponding soluble prepolymers, which are derived from mercaptopropyltrimethoxysilane and [1-(2-aminoethyl)-3-aminopropyl]trimethoxysilane monomers, respectively, on a glass fiber substrate, followed by a cross-linking step at 120 degrees C. The fibers were characterized through infrared spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). These novel materials are extremely efficient in removing low concentrations of mercury and cesium ions from water in the presence of high concentrations of sodium or potassium ions. They were shown to remove trace mercury and cesium contaminants effectively to well below parts per billion concentrations under a variety of conditions.

Removal of Metal Contaminants from Contaminated Saline Waters Using an Iminodiacetic Acid Ion-exchange Resin, Thala Valley Tip, Casey Station, Antarctica

The effect of salinity on the removal of dissolved contaminant metals from water by an Iminodiacetic acid (IDA) ion-exchange resin, Amberlite IRC748, was investigated under batch equilibrium conditions at ambient temperature. The efficiency of contaminant metal removal increased with salinity. The resin was most selective for calcium and magnesium ions at low salinity, and for contaminant metal ions at high salinity. It is proposed that a high concentration of sodium ions limits protonation of the resin, causing a shift from a chelation to an ion-exchange binding mechanism for calcium and magnesium ions.

Optimization of Bifidobacterium longum growth by use of calcium carbonate-alginate beads

High concentrations of ammonium and sodium ions inhibited Bifidobacterium longum growth more than a high calcium ion concentration. The optimal pH for B. longum growth was determined to be 5.0 due to the lower accumulation of ammonium ion. To reduce the accumulation of ammonium ion and obtain an enhanced growth of B. longum, the pH of the culture containing immobilized calcium carbonate beads was controlled to 5.0 with ammonia water. The concentrations of ammonium, sodium, and calcium ions in the culture were maintained at the desired level. The maximum cell mass increased to 16.8 g/l, 1.23 times higher than cultures without calcium carbonate beads. The number of viable cells in the culture increased to 5.0 × 1010, 1.67 times more than cultures without calcium carbonate beads.