High Activity Of Na Research Articles

A multifunctional super‐sodiophilic coating on aluminum current collector for high-performance anode-free Na-metal batteries

Na-metal batteries (NMBs) are drawing soaring research interest as next-generation high-energy and low-cost batteries. However, the pursuit of high-reversibility Na metal anode with controllable and uniform Na plating/stripping remains a formidable challenge owing to the inhomogeneity of mass/charge transfer and high activity of Na. Herein, a 3D Zn@Al current collector is proposed by coating a 3D nanofiber-like Zn layer on the Al foil, which can suppress the dendritic Na growth to enable the high reversibility of Na plating/stripping. Experimental studies and theoretical calculations demonstrate that the 3D Zn@Al current collector greatly enhances the sodiophilicity due to the larger binding energy of Zn/NaZn13 with Na, and homogenizes electric field distribution owing to the 3D nanofiber-like Zn layer. Benefiting from such favorable properties, extraordinary electrochemical performances with low nucleation overpotential (5 mV at 1 mA cm−2), long cycle lifespan (1500 h) together with small polarization voltage (10 mV at 1 mA cm−2) have been achieved. Most noticeably, an anode-free NMBs with Na3V2(PO4)3 as cathode can achieve excellent cycle life (with the capacity retention of 98.8% for 100 cycles). Our findings provide a simple and efficient strategy for designing functional current collector for Na anode to build high-performance anode-free NMBs.

Mineralogical and Isotopic Characteristics of Sodic-Calcic Alteration in the Highland Valley Copper District, British Columbia, Canada: Implications for Fluid Sources in Porphyry Cu Systems

AbstractThe Highland Valley Copper porphyry Cu (±Mo) district is hosted in the Late Triassic Guichon Creek batholith in the Canadian Cordillera. Fracture-controlled sodic-calcic alteration is important because it forms a large footprint (34 km2) outside of the porphyry Cu centers. This alteration consists of epidote ± actinolite ± tourmaline veins with halos of K-feldspar–destructive albite (1–20 XAn) ± fine-grained white mica ± epidote. The distribution of sodic-calcic alteration is strongly influenced by near-orthogonal NE- and SE-trending fracture sets and by proximity to granodiorite stocks and porphyry dikes. Multiple stages of sodic-calcic alteration occurred in the district, which both pre- and postdate Cu mineralization at the porphyry centers.The mineral assemblages and chemical composition of alteration minerals suggest that the fluid that caused sodic-calcic alteration in the Guichon Creek batholith was Cl bearing, at near-neutral pH, and oxidized, and had high activities of Na, Ca, and Mg relative to propylitic and fresh-rock assemblages. The metasomatic exchange of K for Na, localized removal of Fe and Cu, and a paucity of secondary quartz suggest that the fluid was thermally prograding in response to magmatic heating. Calculated δ18Ofluid and δDfluid values of mineral pairs in isotopic equilibrium from the sodic-calcic veins and alteration range from 4 to 8‰ and −20 to −9‰, respectively, which contrasts with the whole-rock values for least altered magmatic host rocks (δ18O = 6.4–9.4‰ and δD = −99 to −75‰). The whole-rock values are suggested to reflect residual magma values after D loss by magma degassing, while the range of hydrothermal minerals requires a mixed-fluid origin with a contribution of magmatic water and an external water source. The O-H isotope results favor seawater as the source but could also reflect the ingress of Late Triassic meteoric water. The 87Sr/86Srinital values of strongly Na-Ca–altered rocks range from 0.703416 to 0.703508, which is only slightly higher than the values of fresh and potassic-altered rocks. Modeling of those data suggests the Sr is derived predominantly from a magmatic source, but the system may contain up to 3% seawater Sr. Supporting evidence for a seawater-derived fluid entrained in the porphyry Cu systems comes from boron isotope data. The calculated tourmaline δ11Bfluid values from the sodic-calcic domains reach 18.3‰, which is consistent with a seawater-derived fluid source. Lower tourmaline δ11Bfluid values from the other alteration facies (4–10‰) suggest mixing between magmatic and seawater-derived fluids in and around the porphyry centers. These results imply that seawater-derived fluids can infiltrate batholiths and porphyry systems at deep levels (4–5 km) in the crust. Sodic ± calcic alteration may be more common in rocks peripheral to porphyry Cu systems hosted in island-arc terranes and submarine rocks than currently recognized.

Processes of formation of fluorite-leucophane-melinophane-eudidymite ores of the Ermakovka F-Be deposit (western Transbaikalia)

Fluorite-leucophane-melinophane-eudidymite ores of zone XVIII of the Ermakovka F-Be deposit were studied by geological, mineralogical, and thermobarogeochemical methods. Contents of Be and impurity elements (Li, Na, Mg, Al, Si, Cl, K, Mn, Fe, Cu, Zn, Nb, Mo, Ag, Sn, W, and Pb) in fluid inclusions in fluorite of this zone have been first determined by LA-ICP-MS. It is shown that fluorite-leucophane-melinophane-eudidymite ores were formed by alkaline high-F low-salt (6.0-12.5 wt.% NaCl equiv) solutions with a relatively low content of Be (0.0002-1.04 g/kg of solution). Fluorite and beryllium minerals were deposited in ores in a wide range of P-T conditions. The early fluorite-phenakite paragenesis formed at high temperatures (480-650 °C) and high pressures (>3 kbar). At the late low-temperature stage, phenakite was replaced by Na-Be silicates (eudidymite and melinophane-leucophane) at <220 °C and <770 bars. The Be-ore deposition was due to the destruction of a predominant beryllium fluoride-carbonate complex as a result of the crystallization of fluorite during the metasomatic replacement of limestones. Eudidymite and melinophane-leucophane formed at low temperatures under high activity of Na and Ca and low activity of Be and F in highly alkaline solutions.

Salinity Tolerance of Two Potato Cultivars (Solanum tuberosum) Correlates With Differences in Vacuolar Transport Activity.

Potato is an important cultivated crop species and since it is moderately salt sensitive there is a need to develop more salt tolerant cultivars. A high activity of Na+ transport across the tonoplast in exchange for H+ is essential to reduce Na+ toxicity. The proton motive force (PMF) generated by the V-H+-ATPase and the V-H+-PPase energizes the Na+(K+)/H+ antiport. We compared the activity, gene expression, and protein levels of the vacuolar proton pumps and the Na+/H+ antiporters in two potato cultivars (Solanum tuberosum) contrasting in their salt tolerance (cv. Desiree; tolerant and Mozart; sensitive) grown at 0 and 60 mM NaCl. Tonoplast-enriched vesicles were used to study the pump activity and protein levels of the V-H+-ATPase and the V-H+-PPase and the activity of the Na+/H+ antiporter. Although salt stress reduced the V-H+-ATPase and the V-H+-PPase activity in both cultivars, the decline in H+ pump activity was more severe in the salt-sensitive cultivar Mozart. After salt treatment, protein amounts of the vacuolar H+ pumps decreased in Mozart but remained unchanged in the cultivar Desiree. Decreased protein amounts of the V-H+-PPase found in Mozart may explain the reduced V-H+-PPase activity found for Mozart after salt stress. Under non-stress conditions, protein amounts of V-H+-PPase were equal in both cultivars while the V-H+-PPase activity was already twice as high and remained higher after salt treatment in the cultivar Desiree as compared to Mozart. This cultivar-dependent V-H+-PPase activity may explain the higher salt tolerance of Desiree. Moreover, combined with reduced vacuolar H+ pump activity, Mozart showed a lower Na+/H+ exchange activity and the Km for Na+ is at least twofold lower in tonoplast vesicles from Desiree, what suggests that NHXs from Desiree have a higher affinity for Na+ as compared to Mozart. From these results, we conclude that the higher capacity in combination with the higher affinity for Na+ uptake can be an important factor to explain the differences in salt tolerance of these two potato cultivars.

Renal excretion of water and electrolytes and plasma monovalent cations in hypertensive patients under psychoemotional stress

Изменение водо- и ионовыделительной функции почки и физико-химического состояния одновалентных катионов плазмы крови у больных гипертонической болезнью при психоэмоциональной нагрузке Dynamics of water and ion renal excretion and physicochemical monovalent cations in hypertensive patients under psychoemotional stress I.E. Ganelina, N.A. Kruchinina, M.N. Maslova, A.A. Panov, E.E. Poroshin Object. To study the influence of psychoemotional stress (PES) on renal mechanisms blood pressure regulation and on the activity of plasma Na + and K + in hypertensive patients. Design and methods. Eighteen males with normal blood pressure and 20 males with hypertension (mean age in both groups - 57 ± 3 years) underwent PES [1], and all of them developed the rise in blood pressure, increased diuresis, natriuresis, renal excretion of K + , osm, clearance of Na-C Na and osm–Cosm. We assessed the levels of Na + and K + in the flame photometer Flafo-40 (Germany), we performed osm-cryoscopy on the thermoelectric milliosmometre (MT-1) to assess the activity of Na + and K + in plasma with the use of ion-selective electrodes ISE-M-K and ISE- M-Na. Results. After PES, SAP and DAP reduced in normotensive and hypertensive patients, however, it was about 12 % remaining above the initial level in both groups. After PES, normotensive subjects increased kidney excretion compared to the initial level: diuresis for 15 %, , U Na V for 15 %, U К V for 18 %, U osm V for 14 %, C Nа for 17 %, C osm for 15 %, i.e. their reabsorption remained low. After PES diuresis, renal excretion of ions, CNa, Cosm are decreased in comparison to baseline level: diuresis, U Na V; U osm V, CNа, C osm were higher for 1-1,3 %. The baseline levels of Na + and K + activity and their activity coefficients were higher in patients in comparison with healthy subjects for 12 %, and the activity coefficient of K + was decreased at PES for 9 %. Conclusion. After PES reabsorption of water, Na + , C Na , Cosm is decreased in normotensive subjects, while in hypertensive patients it significantly increases, despite high blood pressure. The high activity of Na + , and its activity coefficient in patients with hypertension may be associated with a decrease in the proportion of free water in blood plasma.

Erythrocyte ion transport and membrane lipid composition in young and adult rats with NO-deficient hypertension

The aim of our study was to search for abnormalities of sodium and potassium transport in erythrocytes of male Wistar rats subjected to chronic L-NAME treatment (40 mg/kg/day) for 4 weeks either from weaning (4-week-old) or in adulthood (12-week-old). Sodium content, Na +,K +-pump and Na +,K +-cotransport activity, cation leaks as well as membrane cholesterol and phospholipid contents were determined in fresh erythrocytes. Chronic inhibition of NO synthase elicited similar blood pressure rise in both age groups which did not differ in the degree of NO synthase inhibition. No significant ion transport abnormalities were disclosed in erythrocytes of young NO-deficient rats, whereas erythrocyte Na + content, outward Na +,K +-cotransport and inward Na + leak were significantly reduced in adult hypertensive animals compared to age-matched controls. It should be noted that the erythrocytes of adult control rats were characterized by higher activity of Na +,K +-pump and Na +,K +-cotransport, increased Na + and Rb + leaks and elevated membrane cholesterol content compared to those of young normotensive controls. Increased Na + leak and elevated membrane cholesterol content but reduced membrane phosholipid content were revealed in erythrocytes of adult hypertensive rats when compared to young hypertensive rats. It can be concluded that young and adult Wistar rats did not differ in the extent of NO synthase inhibition and blood pressure rise elicited by chronic L-NAME treatment. Our results exclude the important participation of classical sodium transport abnormalities in the pathogenesis of this NO-deficient form of experimental hypertension.

Volume characteristics and element transfer of fenite aureoles: a case study from the Iivaara alkaline complex, Finland

Fenitization in granodioritic rocks has been investigated taking the Iivaara alkaline complex (Finland) as a case study. Five main fenitization reactions responsible for the transition from a granodioritic precursor mineral assemblage to a syenitic or even cancrinite–syenitic mineral assemblage of the fenites are set up. An assessment of element transfer and volume change associated with each of these reactions indicates a general volume loss of about 20% due to fenitization. High activities of Na, Ca, Mg and Fe as well as a low H 2O/CO 2 ratio in the fenitizing fluid phase are indicated. Si, which is the main component released from the precursor rock, was redistributed within the aureole and formed pyroxene dominated mineral assemblages in a reaction with the fenitizing fluid. These vein-type pyroxenites can be found cross-cutting all fenite types. Compositional data of aegirine augite in the fenites reveal disequilibria and feldspar compositions point to minimum temperatures for the production of fenites with syenitic compositions of 660°C and also indicate fast cooling. A Sr isotope characterization of the fenites allows assessment of minimum fluid–rock weight-ratios in the fenite aureole of 0.023–2.3. The element transfer scheme developed in this study is applicable to other localities since many aureoles formed in granitic to granodioritic host rocks have petrographic characteristics similar to the Iivaara fenites.

A comparison of transport-related gill enzyme activities and tissue-specific free amino acid concentrations of Baltic Sea (brackish water) and freshwater threespine sticklebacks, Gasterosteus aculeatus , after salinity and temperature acclimation

The osmoregulatory abilities of one freshwater and two brackish water (Baltic Sea) populations of the euryhaline teleost fish Gasterosteus aculeatus were studied with respect to evolutionary physiology. Plasma osmolality, activities of Na+K+-ATPase, citrate synthase, creatine kinase in the gill and free amino acids in liver, axial muscle and pectoral fin muscle were measured. After transfer from 10 to 35 ppt at 15 °C, time-course changes of plasma osmolality and gill Na+K+-ATPase showed no significant fundamental differences between the freshwater and one of the Baltic Sea populations. In a multi-factorial experiment, each population was exposed to four different abiotic regimes. Both brackish water populations had high mortality in freshwater at 4 °C, which is discussed as a failure of osmotic regulation (reduced taurine concentrations). Freshwater specimens had higher levels of glycine in the axial and pectoral fin muscles compared to the brackish water populations. This is interpreted as a genetically based effect. In brackish (20 ppt) water of 15 °C, the freshwater population had high activities of Na+K+-ATPase, but low activities of creatine kinase, whereas both brackish water populations behaved in the opposite way. A fundamental difference between the freshwater and brackish water populations on the level of the osmoregulatory machinery was not observed.

The ntpJ Gene in the Enterococcus hirae ntp Operon Encodes a Component of KtrII Potassium Transport System Functionally Independent of Vacuolar Na+-ATPase

The ntpJ gene, the tail end in the vacuolar type Na+-ATPase (ntp) operon of Enterococcus hirae, encodes a putative 49-kDa hydrophobic protein resembling K+ transporter protein in Saccharomyces cerevisiae (Takase, K., Kakinuma, S., Yamato, I., Konishi, K., Igarashi, K., and Kakinuma, Y. (1994) J. Biol. Chem. 269, 11037-11044). Northern blotting experiment revealed that the ntpJ gene was transcribed as a cistron in the ntp operon. We constructed an Enterococcus strain in which the ntpJ gene was disrupted by cassette mutagenesis with erythromycin resistance gene. The growth of this mutant was normal at low pH. However, the mutant did not grow at high pH in K+-limited medium (less than 1 mM), while the wild type strain grew well; the internal K+ concentration of this mutant was as low as 7% of that of the wild type strain, suggesting that the K+ accumulation at high pH was inactivated by disruption of the ntpJ gene. Potassium uptake activity via the KtrII system, which had been proposed as the proton potential-independent, Na+-ATPase-coupled system working at high pH (Kakinuma, Y., and Harold, F. M. (1985) J. Biol. Chem. 260, 2086-2091), was missing in this mutant strain. However, this mutant retained as high activities of Na+-ATPase and Na+ pumping as the wild type strain. From these results, we conclude that the NtpJ is a membraneous component of the KtrII K+ uptake system but not a functional subunit of vacuolar Na+-ATPase complex; the interplay between the KtrII system and the Na+-ATPase was discussed.

Na+-K+-adenosine triphosphatase activities in gills of marine teleost fishes: Changes with depth, size and locomotory activity level

Activities of the primary enzyme responsible for monovalent ion regulation, Na+-K+-adenosine triphosphatase (Na+-K+-ATPase), were measured in gills of marine teleost fishes with different depths of occurrence (0 to 4800 m), body weights (a range of five orders of magnitude), and locomotory capacities. Specimens were collected off the coasts of California and Oregon in 1983–1989, and at the Galapagos Spreading Center and 13°N East Pacific Rise hydrothermal vent sites in 1987 and 1988, respectively. Except for two hydrothermal vent fishes, deep-sea species had much lower Na+-K+-ATPase activities g−1 gill filament than shallow-living species, indicating that osmoregulatory costs, like total metabolic rate, are greatly reduced in most deep-living fishes. Within a species, the total branchial Na+-K+-ATPase activity per individual was dependent on size; the average allometric scaling exponent was 0.83. Using published values for oxygen consumption rates, and the total branchial Na+-K+-ATPase activities as an index of osmoregulatory costs, we estimated the maximal cost (as percent of ATP turnover) for osmoregulation in ten teleosts. Osmoregulatory costs averaged about 10% of total ATP turnover among these species, and maximal costs were no greater than about 20%. The percent costs of osmoregulation did not differ between shallow- and deep-living fishes. The reduced total ATP expenditure for osmoregulation in deep-living fishes is proposed to result from the sluggish locomotory habits of these fishes, not from selection for reduced osmotic coastper se. Thus, the reduced swimming abilities of these fishes lead to lower rates of water flow over the gills and less blood flow through the gills due to reduced demands for oxygen. Consequently, passive flux of water and ions through the gills is much lower than in more active fishes, and osmotic costs are thereby minimized. The relatively high activities of Na+-K+-ATPase in gills of the two hydrothermal vent fishes suggest that these fishes may be more active and have higher metabolic rates than other deep-sea fishes.

Branchial and Antennal Gland Na+/K+-Dependent ATPase and Carbonic Anhydrase Activity During Salinity Acclimation of the Euryhaline Crayfish Pacifastacus Leniusculus

SUMMARY Haemolymph and urine electrolyte status and branchial and antennal gland activities of Na+/K+-ATPase and carbonic anhydrase (CA) were determined in the crayfish Pacifastacus leniusculus after 3 weeks acclimation in fresh water (FW) and 350 and 750 mosmol kg−1 sea water (SW). In FW the crayfish maintained haemolymph osmolality around 370 mosmol kg−1 due to hyperionic regulation of the major electrolytes. Involved in this are ion uptake mechanisms situated on the gills, and mechanisms of ion reabsorption from the primary urinary filtrate in the antennal gland (AG). Both of these processes are associated with high activities of Na+/K+-ATPase and CA. The two enzymes are uniformly distributed on gill sets 2– 7, unlike the situation in euryhaline marine species. Additionally, activity levels of both enzymes are extremely high in the AG and can be correlated with the ability to produce a hypo-osmotic urine. In comparison, enzyme activity is negligible in marine species which produce isosmotic urine. Crayfish continued to hyperosmoregulate in 350 mosmol kg−1 SW. High levels of Na+/K+-ATPase confirmed the presence of a component active in the uptake of major electrolytes in the gills and also in the AG, where ion reabsorption persisted. In 750 mosmol kg−1 SW crayfish became isosmotic. Since ATPase is regulated chiefly by deactivation/activation of pre-existing enzyme, overall activity was mostly unchanged. CA activity was significantly reduced in both 350 and 750 mosmol kg−1 SW and correlated with the transition from osmoregulation to osmoconformity, suggesting that it is regulated primarily by deinduction/induction of new enzyme. The difference in the mechanism of regulation exhibited by these two enzymes is believed to relate to their subcellular distribution.

Activity of faujasite-type zeolites in methyl mercaptan — Sulfur dioxide reaction

A higher activity of Na−X than Na−Y in CH3SH+SO2 reaction at 343 was observed. The increase of the copper content in the samples causes an increase of their activity. Water, sulfur, dimethyl disulfide, dimethyl trisulfide and sometimes dimethyl sulfide are registered as reaction products. (CH3)2S3 is formed as a result of the reaction between sulfur and (CH3)2S2.

Respiratory rate and ATP content of stria vascularis of guinea pig in vitro.

Stria vascularis from guinea pig cochleae was incubated in vitro to determine its metabolic response to variations in substrate and ion composition of the incubation medium. The respiratory rate at 37 degrees C in a medium containing glucose and pyruvate as substrate was 17.3 +/- 1.33 (SEM, n = 51) microliter O2/mg dry weight-hour. The stria could not maintain constant respiration by relying solely upon endogenous fuel stores. With substrate supplied, the ATP level could be maintained at about 73% of that existing in vivo. Glucose appears to be an adequate substrate for stria in vitro since glutamate, pyruvate, and fumarate did not increase the respiratory rate. Succinate increased respiration markedly but did not increase the ATP level. Ouabain (10(-4) M) caused a 48% decrease in the respiratory rate. Incubation in Na+-free and K"-free medium, each resulted in irreversible decrease of respiratory rate comparable to (or greater than) that caused by ouabain. These data are in accord with the high activity of Na+-K+-ATPase in the stria and the pronounced sensitivity of the endolymphatic potential to ouabain.

Studies on neuronal lipid.

The procedure for bulk preparation of nerve-cell perikarya from pig brain-stem is briefly described. This method has definite merits with regard to the preservation of the intracellular structures as well as the preservation of the processes. The chemical composition of the isolated nerve-cell perikarya is presented. The nerve-cell perikarya are characterized by the absence of cerebroside and sulfatide. Diffuse distribution of ganglioside on the cell surface is suggested. The lipid content of the nerve-cell perikarya isolated by different methods is discussed. Lipid composition of the invertebrate nervous tissue is discussed. The submicrosomal membranes of rat brain are isolated, and their chemical and morphological properties are discussed. Ribosome-free membranes are characterized by the high content of glycolipids including gangliosides, as well as by the high activity of Na, K-ATPase, whereas ribosome-bound membranes are characterized by the absence of glycolipids, as well as by the low activity of Na, K-ATPase. The molecular organizations of lipid in submicrosomal membranes are demonstrated.

IN SITU MEASUREMENT OF DISSOLVED MATERIALS AS AN INDICATOR OF ORGANIC TERRAIN TYPE

Portable equipment has been used to measure selected environmental parameters in situ. A battery-operated potentiometer used in conjunction with several specific ion electrodes, a platinum redox electrode, and a combination pH electrode were used to obtain ion activity, pH, and Eh measurements of natural systems. In addition, dissolved oxygen concentration was measured using an oxygen electrode and battery-operated meter. Results from the analysis of several streams are presented to illustrate the application of the technique to field measurements of streams as an indicator of environmental disturbance. Information collected also allowed for the differentiation of different types of organic terrain based on the dissolved load of the saturated organic materials. The terrain type referred to as fen had a higher activity of Na, Cl, and Ca, a higher pH value, and a lower concentration of oxygen than the bog terrain type. These results are explained with reference to organic terrain morphology and the distribution of permafrost in the study area.