Search results for "electrolytes"

Ion transport and selectivity in nanopores with spatially inhomogeneous fixed charge distributions

2007

Polymeric nanopores with fixed charges show ionic selectivity when immersed in aqueous electrolyte solutions. The understanding of the electrical interaction between these charges and the mobile ions confined in the inside nanopore solution is the key issue in the design of potential applications. The authors have theoretically described the effects that spatially inhomogeneous fixed charge distributions exert on the ionic transport and selectivity properties of the nanopore. A comprehensive set of one-dimensional distributions including the skin, core, cluster, and asymmetric cases are analyzed on the basis of the Nernst-Planck equations. Current-voltage curves, nanopore potentials, and tr…

An efficient dissipative particle dynamics-based algorithm for simulating electrolyte solutions

2015

We propose an efficient simulation algorithm based on the dissipative particle dynamics (DPD) method for studying electrohydrodynamic phenomena in electrolyte fluids. The fluid flow is mimicked with DPD particles while the evolution of the concentration of the ionic species is described using Brownian pseudo particles. The method is designed especially for systems with high salt concentrations, as explicit treatment of the salt ions becomes computationally expensive. For illustration, we apply the method to electro-osmotic flow over patterned, superhydrophobic surfaces. The results are in good agreement with recent theoretical predictions.

Modelling of natural and synthetic polyelectrolyte interactions in natural waters.

2006

In this paper SIT and Pitzer models are used for the first time to describe the interactions of natural and synthetic polyelectrolytes in natural waters. Measurements were made potentiometrically at 25 °C in single electrolyte media, such as Et4NI and NaCl (for fulvic acid 0.1 < I /mol L− 1 < 0.75), and in a multi-component medium simulating the composition of natural waters at a wide range of salinities (for fulvic and alginic acids: 5 < S < 45) with particular reference to sea water [Synthetic Sea Water for Equilibrium studies, SSWE]. In order to simplify calculations, SSWE was considered to be a “single salt” BA, with cation B and anion A representing all the major cations (Na+, K+, Mg2+…

Suitability of non-glucose-carbohydrates for parenteral nutrition

1975

Postoperative parenteral nutrition can only be optimally effective if the characteristics of post-traumatic metabolism are taken into account. Two main possibilities are discussed for the carbohydrate component of parenteral nutrition during this phase: glucose with high doses of insulin or non-glucose carbohydrates (sugar substitutes) possibly in a suitable combination with glucose. The risks as well as the technical and organisational problems involved in the use of them are discussed and the authors prefer the second of the two alternatives. Possible side effects of non-glucose carbohydrates are pointed out and it is shown how these can be avoided by observing dose guidelines. So far a c…

Polymer electrolytes based on PAN and mixed salts for photoelectrochemical appilcations: formulation and characterization

2012

Novel cationic copolymers of a polyasparthylhydrazide: synthesis and characterization.

2005

Alpha,beta-poly(asparthylhydrazide) (PAHy), a water soluble synthetic polymer, was functionalized by using EDCI chemistry with 3-(carboxypropyl)trimethyl-ammonium chloride (CPTACl) obtaining carboxypropyltrimethyl ammonium copolymers (PAHy-CPTA). Three PAHy-CPTA copolymers at increasing derivatization degrees (38%, 48%, 58%) were chosen for subsequent investigations. The capability of these copolymers to bind, neutralize, and protect DNA against degradation by DNase II was evalued by gel retardation assay and DNA degradation test at pH 5.5. Zeta potential measurements show that all studied polymers are able to neutralize the anionic charge of DNA at polymer/DNA weight ratio in the range of …

Efficient size control of copper nanoparticles generated in irradiated aqueous solutions of star-shaped polyelectrolyte containers

2015

Physical chemistry, chemical physics 17(17), 11490-11498(2015). doi:10.1039/C5CP00269A

Polyanion–tobramycin nanocomplexes into functional microparticles for the treatment of Pseudomonas aeruginosa infections in cystic fibrosis

2016

Aim: Efficacy of antibiotics in cystic fibrosis (CF) is compromised by the poor penetration through mucus barrier. This work proposes a new ‘nano-into-micro’ approach, used to obtain a combinatorial effect: achieve a sustained delivery of tobramycin and overcome mucus barrier. Methods: Mannitol microparticles (MPs) were loaded with a tobramycin polymeric nanocomplex and characterized in presence of CF artificial mucus. Results &amp; discussion: MPs are able to alter the rheological properties of CF artificial mucus, enhancing drug penetration into it and allowing a prolonged drug release. MPs resulted to be effective in Pseudomonas aeruginosa infections if compared with free tobramycin. Co…

Initial topical cooling followed by backtable Celsior flush perfusion provides excellent early graft function in porcine single lung transplantation …

2013

Topical in situ cooling of the donor lungs is a prerequisite for procurement of non-heart-beating donor lungs and may be of interest for living related lung donation.Twenty-four single lung transplants were performed in 4 groups of Landrace pigs (6 per group). Control LPD, control Celsior and topical cooling in situ, followed by LPD (exLPD) or Celsior (exCel) ex situ flush, were employed. All lungs were perfused antegrade with 1 liter of solution at 4°C. Lungs were stored immersed in preservation solution for 24 hours at 4°C. After transplantation of the left lung, the right recipient bronchus and pulmonary artery were clamped.Four of 6 animals each in the LPD and Celsior groups and all 6 a…

Blocking of an ion channel by a highly charged drug: Modeling the effects of applied voltage, electrolyte concentration, and drug concentration

2005

We present a simple physical model to estimate the blocked pore probability of an ion channel that can be blocked by a highly charged drug in solution. The model is inspired by recent experimental work on the blocking of the ${\mathrm{PA}}_{63}$ channel, involved in the anthrax toxin infection, by a highly charged drug [Karginov et al. PNAS 102, 15075 (2005)]. The drug binding to the pore is highly specific but the strong dependence of blocking on the applied voltage and electrolyte concentration suggests that long range electrostatic interactions are important. Since basic electrostatic concepts rather than detailed molecular models are considered, the microscopic details of the channel bl…