Search results for "PLASMA"
showing 10 items of 4043 documents
Approximating hidden chaotic attractors via parameter switching.
2018
In this paper, the problem of approximating hidden chaotic attractors of a general class of nonlinear systems is investigated. The parameter switching (PS) algorithm is utilized, which switches the control parameter within a given set of values with the initial value problem numerically solved. The PS-generated attractor approximates the attractor obtained by averaging the control parameter with the switched values, which represents the hidden chaotic attractor. The hidden chaotic attractors of a generalized Lorenz system and the Rabinovich-Fabrikant system are simulated for illustration. In Refs. 1–3, it is proved that the attractors of a chaotic system, considered as the unique numerical …
A Coherent derivation of an average ion model including the evolution of correlations between different shells
2013
We propose in this short note a method enabling to write in a systematic way a set of refined equations for average ion models in which correlations between populations are taken into account, starting from a microscopic model for the evolution of the electronic configura- tion probabilities. Numerical simulations illustrating the improvements with respect to standard average ion models are presented at the end of the paper.
Development and validation of a micellar liquid chromatographic method to determine three antitumorals in plasma
2017
Aim: A micellar liquid chromatographic method to determine several anticancer drugs (pazopanib, dabrafenib and regorafenib) in plasma was developed and validated by the guidelines of the EMA. Experimental: Plasma samples were directly injected, after a 1/5-dilution in a micellar solution. The drugs were resolved in <18 min using a C18 column. The mobile phase was an aqueous solution of 0.12 M SDS – 2% 1-pentanol, buffered at pH 7. The detection was performed by absorbance at 260 nm. Results: The values of the main validation parameters were: LOD (0.1–1 mg/l), calibration range (0.2–2 to 80 mg/l), accuracy (-12.5 to +11.7%) and precision (<11.9%). Conclusion: The procedure was conduct…
Strategies for improving production and purification of a recombinant protein: rP30 of Toxoplasma gondii expressed in the yeast Schizosaccharomyces p…
2007
Abstract Many problems concerned with the production and the purification of recombinant proteins must be addressed prior to launching an industrial production process. Among these problems, attention is focused on low-level expression that complicates the purification step and can jeopardise the process. The expression of a membrane protein, rP30, of Toxoplasma gondii in the yeast Schizosaccharomyces pombe led to a secretion of only 0.5 μg ml−1. In order to obtain a sufficient quantity for biochemical characterization and evaluation in vitro diagnostic test development, strategies for both production and purification had to be optimized. First, the influence of four nitrogen sources (three…
Evaluation of enantioselective binding of propanocaine to human serum albumin by ultrafiltration and electrokinetic chromatography under intermediate…
2011
Abstract Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. In this paper, the enantioselective binding of propanocaine (PRO) enantiomers to human serum albumin (HSA), the most relevant plasmatic protein in view of stereoselectivity, has been evaluated by incubation and ultrafiltration of racemic PRO–HSA mixtures and chiral analysis of the bound and unbound fractions by electrokinetic chromatography using HSA as chiral selector. Experimental conditions for the separation of PRO enantiomers using HSA as chiral selector and electrokinetic chromatography have been optimised. Affinity constants and protein bi…
Evaluation of Clotting Factor Concentrates for Treatment of Thrombotic Thrombocytopenic Purpura.
2010
Abstract Abstract 3678 Introduction: Thrombotic thrombocytopenic purpura (TTP) is characterized by microthrombi, hemolytic anemia as well as thrombocytopenia. These symptoms are caused by a decreased activity of the protease ADAMTS13 which cleaves the von Willebrand Factor (VWF), due to mutation of the ADAMTS13-gene or autoantibodies. At the moment, the only available immediate therapy is plasmapheresis with Fresh Frozen Plasma (FFP) which may induce side effects. Therefore an alternative therapy might be the treatment with clotting factor concentrates. Methods: 40 plasma samples were tested, consisting of FFP and solvent/detergent treated plasma, four batches of each blood group; VWF/VIII …
Wind tunnel study on the size distribution of droplets after collision induced breakup of levitating water drops
2018
Abstract Wind tunnel experiments on collisions between drop pairs of 2.5 and 0.5 mm diameter have been performed and the coalescence and breakup events have been recorded by a high-speed digital camera. From the comprehensive analysis of the captured images, the most important parameters utilized in numerical models, such as coalescence efficiency, breakup type, number of fragments and fragment size distribution after breakup were determined. The experimentally obtained parameters have been compared to parameterizations based on earlier laboratory studies of Low and List, and on direct numerical simulations. A very good agreement between experimental results and parameterizations has been f…
Laser-Induced Plasma Emission Spectrometric Study of Pigments and Binders in Paper Coatings: Matrix Effects
1998
Laser-induced plasma emission spectroscopy (LIPS) has been used to study inorganic pigment and organic binder distributions in paper coatings, which are inhomogeneous and porous materials. The plasma was generated by focusing a pulsed XeCl excimer laser beam (diameter 100 μm, irradiance 0.3 GW/cm2) on the sample surface at atmospheric pressure. A gated intensified CCD detector was used to record time-delayed emission spectra. Linear correlations between the LIPS signals and the coat weight and the binder content of the coatings studied were obtained. Emission line intensities from ionic and neutral magnesium atoms were used to evaluate plasma temperature corrections in determining silicon a…
Active spike transmission in the neuron model with a winding threshold manifold
2012
International audience; We analyze spiking responses of excitable neuron model with a winding threshold manifold on a pulse stimulation. The model is stimulated with external pulse stimuli and can generate nonlinear integrate-and-fire and resonant responses typical for excitable neuronal cells (all-or-none). In addition we show that for certain parameter range there is a possibility to trigger a spiking sequence with a finite number of spikes (a spiking message) in the response on a short stimulus pulse. So active transformation of N incoming pulses to M (with M>N) outgoing spikes is possible. At the level of single neuron computations such property can provide an active "spike source" comp…
Flow properties and hydrodynamic interactions of rigid spherical microswimmers.
2017
We analyze a minimal model for a rigid spherical microswimmer and explore the consequences of its extended surface on the interplay between its self-propulsion and flow properties. The model is the first order representation of microswimmers, such as bacteria and algae, with rigid bodies and flexible propelling appendages. The flow field of such a microswimmer at finite distances significantly differs from that of a point-force (Stokeslet) dipole. For a suspension of microswimmers, we derive the grand mobility matrix that connects the motion of an individual swimmer to the active and passive forces and torques acting on all the swimmers. Our investigation of the mobility tensors reveals tha…