A comparison of the effects of ibuprofen and indomethacin upon renal haemodynamics and electrolyte excretion in the presence and absence of frusemide

1. This study has compared the effects of ibuprofen and indomethacin upon renal haemodynamics, electrolyte excretion and renin release in the presence and absence of frusemide under sodium replete conditions in eight healthy volunteers. 2. Neither ibuprofen (400 mg and 800 mg) nor indomethacin (50 mg) affected renal blood flow, glomerular filtration rate or electrolyte excretion in the basal state. 3. Frusemide had no effect on renal blood flow, but significantly increased glomerular filtration rate. This latter change was suppressed significantly only by ibuprofen 400 mg. Frusemide-induced diuresis was inhibited by all treatments, while natriuresis following frusemide was inhibited by indomethacin only. 4. Significant increments in plasma renin activity, which were suppressed by all treatments, were observed after frusemide. The degree of inhibition of the renin responses was significantly greater in the presence of indomethacin than with either dose of ibuprofen. 5. In a sodium replete setting in healthy volunteers, indomethacin and ibuprofen had no detrimental effects on basal renal function. In the presence of frusemide, indomethacin had more anti-natriuretic and renin-suppressing effect than ibuprofen. There was no evidence for a dose-related effect of ibuprofen.

The partially reversible formation of Li-metal particles on a solid Li electrolyte:applications toward nanobatteries

The feasibility of large-scale implementation of Li-air batteries (LABs) hinges on understanding the thermodynamic and kinetic factors that control charge-discharge rates, efficiency and life times. Here, the kinetics of bias-induced reactions is explored locally on the surface of Li-ion conductive glass ceramics, a preferred electrolyte for LABs, using direct current-voltage and strain spectroscopies. Above a critical bias, particle growth kinetics were found to be linear in both the bias and time domains. Partial reversibility was observed for Li particles as evidenced by the presence of anodic peaks following the Li(+) reduction, as well an associated reduction in particle height. The degree of reversibility was highest for the smallest particles formed. These observations thus suggest the possibility of producing nanobatteries with an active anode volume of the order of 0.1 al.

Physical properties of a new Deep Eutectic Solvent based on lithium bis[(trifluoromethyl)sulfonyl]imide and N-methylacetamide as superionic suitable electrolyte for lithium ion batteries and electric double layer capacitors

Herein we present a study on the physical/chemical properties of a new Deep Eutectic Solvent (DES) based on N-methylacetamide (MAc) and lithium bis[(trifluoromethyl)sulfonyl]imide (LiTFSI). Due to its interesting properties, such as wide liquid-phase range from -60°C to 280°C, low vapor pressure, and high ionic conductivity up to 28.4mScm at 150°C and at x=1/4, this solution can be practically used as electrolyte for electrochemical storage systems such as electric double-layer capacitors (EDLCs) and/or lithium ion batteries (LiBs). Firstly, relationships between its transport properties (conductivity and viscosity) as a function of composition and temperature were discussed through Arrhenius' Law and Vogel-Tamman-Fulcher (VTF) equations, as well as by using the Walden classification. From this investigation, it appears that this complex electrolyte possesses a number of excellent transport properties, like a superionic character for example. Based on which, we then evaluated its electrochemical performances as electrolyte for EDLCs and LiBs applications by using activated carbon (AC) and lithium iron phosphate (LiFePO) electrodes, respectively. These results demonstrate that this electrolyte has a good compatibility with both electrodes (AC and LiFePO) in each testing cell driven also by excellent electrochemical properties in specific capacitance, rate and cycling performances, indicating that the LiTFSI/MAc DES can be a promising electrolyte for EDLCs and LiBs applications especially for those requiring high safety and stability. © 2013 Elsevier Ltd.

Comparative study on performances of trimethyl-sulfonium and trimethyl-ammonium based ionic liquids in molecular solvents as electrolyte for electrochemical double layer capacitors

The present work reports a comparative study on the performances of two bis[(trifluoromethyl)sulfonyl]imide-based protic (PIL) and aprotic (AIL) ionic liquids, namely, trimethyl-ammonium bis[(trifluoromethyl)sulfonyl]imide ([HN][TFSI], PIL) and trimethyl-sulfonium bis[(trifluoromethyl) sulfonyl]imide ([S][TFSI], AIL), as mixtures with three molecular solvents: gamma butyrolactone (?-BL), propylene carbonate (PC), and acetonitrile (ACN) as electrolytes for supercapacitor applications. After an analysis of their transport properties as a function of temperature, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements were conducted at 25 and -30 C to investigate the performance of these mixtures as electrolytes for supercapacitors using activated carbon as the electrode material. Surprisingly, for each solvent investigated, no significant differences were observed between the electrolytes based on the PIL and AIL in their electrochemical performance due to the presence or the absence of the labile proton. Furthermore, good specific capacitances were observed in the case of ?-BL-based electrolytes even at low temperature. Capacitances up to 131 and 80 F·g are observed for the case of the [S][TFSI] + ?-BL mixture at 25 and -30 C, respectively. This latter result is very promising particularly for the formulation of new environmentally friendly electrolytes within energy storage systems even at low temperatures. © 2013 American Chemical Society.

Trimethoxymethane as an alternative fuel for a direct oxidation PBI polymer electrolyte fuel cell

The oxidation of trimethoxymethane (TMM) (trimethyl orthoformate) in a direct oxidation PBI fuel cell was examined by on-line mass spectroscopy and on-line FTIR spectroscopy. The results show that TMM was almost completely hydrolyzed in a direct oxidation fuel cell which employs an acid doped polymer electrolyte to form a mixture of methylformate, methanol and formic acid. It also found that TMM was hydrolyzed in the presence of water at 120°C even without acidic catalyst. The anode performance improves in the sequence of methanol, TMM, formic acid/methanol, and methylformate solutions. Since formic acid is electrochemically more active than methanol, these results suggest that formic acid is probably a key factor for the improvement of the anode performance by using TMM instead of methanol under these conditions. © 1998 Elsevier Science Ltd. All rights reserved.

Polymer electrolyte membrane water electrolyser with Aquivion short side chain perfluorosulfonic acid ionomer binder in catalyst layers

The Aquivion short-side-chain (SSC) perfluorosulfonic acid (PFSA) ionomer was adopted in catalyst layers (CL) of polymer electrolyte membrane water electrolysers (PEMWE) instead of long-side-chain (LSC) Nafion ionomer. The effects of SSC ionomer content in CL for oxygen evolution reaction were studied in half cell with cyclic voltammetry and steady state linear sweep. In a single cell test the MEA with SSC-PFSA Aquivion ionomer exhibited better thermal stability than the one with LSC-PFSA Nafion ionomer at 90 °C. The cell voltage at a current density of 1 A cm was 1.63 V at 90 °C using the SSC-PFSA Aquivion ionomer binder, Nafion 117 membrane, and without back pressurizing. In a continuous operation the cell voltage degradation rate of the MEA using Aquivion ionomer binder was only about 0.82 mV h.

Development of fractional order capacitors based on electrolyte processes

In recent years, significant research in the field of electrochemistry was developed. The performance of electrical devices, depending on the processes of the electrolytes, was described and the physical origin of each parameter was established. However, the influence of the irregularity of the electrodes was not a subject of study and only recently this problem became relevant in the viewpoint of fractional calculus. This paper describes an electrolytic process in the perspective of fractional order capacitors. In this line of thought, are developed several experiments for measuring the electrical impedance of the devices. The results are analyzed through the frequency response, revealing capacitances of fractional order that can constitute an alternative to the classical integer order elements. Fractional order electric circuits are used to model and study the performance of the electrolyte processes.

Water and electrolyte content and distribution in tissues of thermally-acclimated rainbow trout, Salmo gairdneri

The primary objective of this investigation was that of providing a comprehensive tissue-by-tissue assessment of water-electrolyte status in thermally-acclimated rainbow trout, Salmo gairdneri. To this end levels of water and the major ions, sodium, chloride and potassium were evaluated in the plasma, at three skeletal muscle sites, and in cardiac muscle, liver, spleen, gut and brain of animals acclimated to 2°, 10° and 18°C. The occurrence of possible seasonal variations in water-electrolyte balance was evaluated by sampling sununer and late fall-early winter populations of trout. On the basis of values for water and electrolyte content, estimates of extracellular and cellular phase volumes, cellular electrolyte concentrations and Nernst equilibrium potentials were made. Since accurate assessment of the extracellular phase volume is critical in the estimation of cellular electrolyte concentrations and parameters based on assumed cellular ion levels, [14 C]-polyethylene glycol-4000, which is assumed to be confined to the extracellular space, was employed to provide comparisons with various ion-defined spaces (H20~~s, H20~~/K and H20~~s). Subsequently, the ion-defined space yielding the most realistic estimate of extracellular phase volume for each tissue was used in cellular electrolyte calculations. Water and electrolyte content and distribution varied with temperature. Tissues, such as liver, spleen and brain appeared to be the most thermosensitive, whereas skeletal and cardiac muscle and gut tissue were less influenced. 'Summer' series trout appeared to be more capable of maintaining their water- electrolyte balance than the ~fall-winter' series animals. i The data are discussed in terms of their possible effect on maintenance of appropriate cellular metabolic and electrophysiological functions.

Application of laser beam deflection technique to study the diffusion process in electrolyte solutions

A simple method based on laser beam deflection to study the variation of diffusion coefficient with concentration in a solution is presented. When a properly fanned out laser beam is passed through a rectangular cell filled with solution having concentration gradient, the emergent beam traces out a curved pattern on a screen. By taking measurements on the pattern at different concentrations, the variation of diffusion coefficient with concentration can be determined.

Agonists of protease-activated receptors 1 and 2 stimulate electrolyte secretion from mouse gallbladder

Cholecystitis is one of the most common gastrointestinal diseases. Inflammation induces the activation of proteases that can signal to cells by cleaving protease-activated receptors (PARs) to induce hemostasis, inflammation, pain, and repair. However, the distribution of PARs in the gallbladder is unknown, and their effects on gallbladder function have not been fully investigated. We localized immunoreactive PAR(1) and PAR(2) to the epithelium, muscle, and serosa of mouse gallbladder. mRNA transcripts corresponding to PAR(1) and PAR(2), but not PAR(4), were detected by RT-PCR and sequencing. Addition of thrombin and a PAR(1)-selective activating peptide (TFLLRN-NH(2)) to the serosal surface of mouse gallbladder mounted in an Ussing chamber stimulated an increase in short-circuit current in wild-type but not PAR(1) knockout mice. Similarly, serosally applied trypsin and PAR(2) activating peptide (SLIGRL-NH(2)) increased short-circuit current in wild-type but not PAR(2) knockout mice. Proteases and activating peptides strongly inhibited electrogenic responses to subsequent stimulation with the same agonist, indicating homologous desensitization. Removal of HCO(3)(-) ions from the serosal buffer reduced responses to thrombin and trypsin by >80%. Agonists of PAR(1) and PAR(2) increase intracellular Ca(2+) concentration in isolated and cultured gallbladder epithelial cells. The COX-2 inhibitor meloxicam and an inhibitor of CFTR prevented the stimulatory effect of PAR(1) but not PAR(2). Thus PAR(1) and PAR(2) are expressed in the epithelium of the mouse gallbladder, and serosally applied proteases cause a HCO(3)(-) secretion. The effects of PAR(1) but not PAR(2) depend on generation of prostaglandins and activation of CFTR. These mechanisms may markedly influence fluid and electrolyte secretion of the inflamed gallbladder when multiple proteases are generated.

Capacitive electrolyte-insulator-semiconductor structures functionalised with a polyelectrolyte/enzyme multilayer: New strategy for enhanced field-effect biosensing

A novel strategy for enhanced field-effect biosensing using capacitive electrolyte-insulator-semiconductor (EIS) structures functionalised with pH-responsive weak polyelectrolyte/enzyme or dendrimer/enzyme multilayers is presented. The feasibility of the proposed approach is exemplarily demonstrated by realising a penicillin biosensor based on a capacitive p-Si-SiO(2) EIS structure functionalised with a poly(allylamine hydrochloride) (PAH)/penicillinase and a poly(amidoamine) dendrimer/penicillinase multilayer. The developed sensors response to changes in both the local pH value near the gate surface and the charge of macromolecules induced via enzymatic reaction, resulting in a higher sensitivity. For comparison, an EIS penicillin biosensor with adsorptively immobilised penicillinase has been also studied. The highest penicillin sensitivity of 100 mV/dec has been observed for the EIS sensor functionalised with the PAH/penicillinase multilayer. The lower and upper detection limit was around 20 mu M and 10 mM, respectively. In addition, an incorporation of enzymes in a multilayer prepared by layer-by-layer technique provides a larger amount of immobilised enzymes per sensor area, reduces enzyme leaching effects and thus, enhances the biosensor lifetime (the loss of penicillin sensitivity after 2 months was 10-12%). (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

All solid-state electrochromic devices with gelatin-based electrolyte

6 x 8cm(2) electrochromic devices (ECDs) with the configuration K-glass/EC-layer/electrotype/ion-storage (IS) layer/K-glass, have been assembled using Nb2O5:Mo EC layers, a (CeO2)(0.81)-TiO2 IS-layer and a new gelatin electrolyte containing Li+ ions. The structure of the electrolyte is X-ray amorphous. Its ionic conductivity passed by a maximum of 1.5 x 10(-5) S/CM for a lithium concentration of 0.3g/15ml. The value increases with temperature and follows an Arrhenius law with an activation energy of 49.5 kJ/mol. All solid-state devices show a reversible gray coloration, a long-term stability of more than 25,000 switching cycles (+/- 2.0 V/90 s), a transmission change at 550 nm between 60% (bleached state) and 40% (colored state) corresponding to a change of the optical density (Delta OD = 0. 15) with a coloration efficiency increasing from 10cm(2)/C (initial cycle) to 23cm(2)/C (25,000th cycle). (c) 2007 Elsevier B.V. All rights reserved.

The effects of hydrogen sulfide on the polymer electrolyte membrane fuel cell anode catalyst: H(2)S-Pt/C interaction products

The performance of a polymer electrolyte membrane fuel cell (PEMFC) operating on a simulated hydrocarbon reformate is described. The anode feed stream consisted of 80% H(2),similar to 20% N(2), and 8 ppm hydrogen sulfide (H(2)S). Cell performance losses are calculated by evaluating cell potential reduction due to H(2)S contamination through lifetime tests. It is found that potential, or power, loss under this condition is a result of platinum surface contamination with elemental sulfur. Electrochemical mass spectroscopy (EMS) and electrochemical techniques are employed, in order to show that elemental sulfur is adsorbed onto platinum, and that sulfur dioxide is one of the oxidation products. Moreover, it is demonstrated that a possible approach for mitigating H(2)S poisoning on the PEMFC anode catalyst is to inject low levels of air into the H(2)S-contaminated anode feeding stream. (C) 2011 Elsevier B.V. All rights reserved.

Amylopectin-rich starch plasticized with glycerol for polymer electrolyte application

This paper describes the preparation and characterization of a solid polymer electrolyte based on amylopectin-rich starch plasticized with glycerol. The samples were characterized through ionic conductivity (sigma) measurements, scanning electron microscopy, thermal analysis, and spectroscopy in the UV-Vis-NIR region. The results showed that the highest sigma (1.1 x 10(-4) Scm(-1) at 30 degrees C) was obtained for the sample with n = [O]/[Li] = 6.5 ratio. In addition, the samples plasticized with 30-35 wt.% of glycerol presented high ionic conductivity, transparency and conduction stability. The ionic conductivity measurements as a function of lithium salt contents showed a maximum for n=6.5. The ionic conductivity as a function of time for amylopectin-rich starch plasticized with 30 wt.% of glycerol and containing [O]/[Li] = 10 showed conduction stability over 6 months (sigma similar to 3.01 x 10(-5) S cm(-1)). (C) 2010 Elsevier B.V. All rights reserved.