Steady state pharmacokinetic profile of indomethacin in elderly patients and young volunteers

The steady-state pharmacokinetic profile of indomethacin was examined in twelve healthy volunteers (4 m, 8 f; 20-34 y) and in 12 elderly subjects (7 m, 5 f; 70-88 y). Two formulations of indomethacin were examined, providing duplicate data for each subject group. The subjects received each formulation of indomethacin (25 mg tid) for 6 days in a single blind crossover fashion. On day 7, after an overnight fast, a final 25 mg dose of indomethacin was given and plasma concentrations measured over the following 12 h. Kinetic parameters Cpmin, Tmax and AUC (0-12 h) were determined. There were no differences in the pharmacokinetic parameters between young and elderly subjects or between data for the two formulations of indomethacin. AUC values (micrograms.ml-1.h), for example, for the two formulations in the young subjects were 5.85 and 6.85 while the values for the elderly subjects were 6.55 and 6.50 respectively. When each treatment period was considered independently there was a significant difference between young and elderly subjects with regard to compliance. The rates of non compliance (over and under compliance) using a capsule count technique were, however, low with a mean maximum value of 5.8% being recorded for the elderly subjects.

Kinetics of liquid phase semiconductor photoassisted reactions: Supporting observations for a pseudo-steady-state model

The kinetics of liquid phase semiconductor photocatalytic and photoassisted reactions are an area of some debate, reignited recently by an article by Ollis(1) in which he proposed a simple pseudo- steady- state model to interpret the Langmuir- Hinshelwood type kinetics, commonly observed in such systems. In the current article, support for this model, over other models, is provided by a reinterpretation of the results of a study, reported initially in 1999,2 of the photoassisted mineralization of 4- chlorophenol, 4-CP, by titania films and dispersions as a function of incident light intensity, I. On the basis of this model, these results indicate that 4- CP is adsorbed more strongly on P25 TiO2 when it is in a dispersed, rather than a film form, due to a higher rate constant for adsorption, k(1). In addition, the kinetics of 4- CP removal appear to depend on I-beta where, beta = 1 or 0.6 for when the TiO2 is in a film or a dispersed form, respectively. These findings are discussed both in terms of the pseudo- steady- state model and other popular kinetic models.

STEADY-STATE SOLUTIONS IN NONLINEAR DIFFUSIVE SHOCK ACCELERATION

<p>Stationary solutions to the equations of nonlinear diffusive shock acceleration play a fundamental role in the theory of cosmic-ray acceleration. Their existence usually requires that a fraction of the accelerated particles be allowed to escape from the system. Because the scattering mean free path is thought to be an increasing function of energy, this condition is conventionally implemented as an upper cutoff in energy space-particles are then permitted to escape from any part of the system, once their energy exceeds this limit. However, because accelerated particles are responsible for the substantial amplification of the ambient magnetic field in a region upstream of the shock front, we examine an alternative approach in which particles escape over a spatial boundary. We use a simple iterative scheme that constructs stationary numerical solutions to the coupled kinetic and hydrodynamic equations. For parameters appropriate for supernova remnants, we find stationary solutions with efficient acceleration when the escape boundary is placed at the point where growth and advection of strongly driven nonresonant waves are in balance. We also present the energy dependence of the distribution function close to the energy where it cuts off-a diagnostic that is in principle accessible to observation.</p>

Transferring entanglement to the steady state of flying qubits

<p>The transfer of entanglement from optical fields to qubits provides a viable approach to entangling remote qubits in a quantum network. In cavity quantum electrodynamics, the scheme relies on the interaction between a photonic resource and two stationary intracavity atomic qubits. However, it might be hard in practice to trap two atoms simultaneously and synchronize their coupling to the cavities. To address this point, we propose and study entanglement transfer from cavities driven by an entangled external field to controlled flying qubits. We consider two exemplary non-Gaussian driving fields: NOON and entangled coherent states. We show that in the limit of long coherence time of the cavity fields, when the dynamics is approximately unitary, entanglement is transferred from the driving field to two atomic qubits that cross the cavities. On the other hand, a dissipation-dominated dynamics leads to very weakly quantum-correlated atomic systems, as witnessed by vanishing quantum discord.</p>

Conductivity sensor technology application in steady state migration test

<p>In this paper the current development of the steady state migration test was reviewed. Experiments were carried out for a series of concrete mixes with the steady state migration test in which conductivity sensor technology is applied. With the developed steady state migration test, conductivity in anolyte, loop current and temperature can be monitored in real time. The experimental results are conductive to understand the mechanism of chloride migration during both unsteady state and steady state. The conductivity of anolyte could be used to calculate the chloride concentration in anolyte and the theoretical correlation between them was explained. Over all, the developed steady state migration is an effective, convenient, well-defined in theory and plentiful with information method which could be used to determine the chloride diffusion coefficient of cementitious materials.</p>

Quasi steady state and dynamic hygrothermal performance of fibrous Hemp and Stone Wool insulations: Two innovative laboratory based investigations

Moisture and heat management properties of Hemp and Stone Wool insulations were studied by mounting them between a hot and a cold climate chamber. Both insulations were exposed to identical hygrothermal boundary conditions. Quasi steady state and dynamic tests were carried out at a range of relative humidity exposures. The likelihood of interstitial condensation was assessed and equivalent thermal conductivity values of the insulations were determined. The adsorption-desorption isotherms of the insulations were also determined in a dynamic vapour sorption (DVS) instrument. It was observed that the likelihood of condensation was higher in Stone Wool insulation than in Hemp insulation. Hemp insulation performed better in managing moisture due to its high hygric inertia and water absorption capacity. It was observed that the equivalent thermal conductivity of Stone Wool insulation was dependent on enthalpy flow and phase change of moisture. The equivalent thermal conductivity of Hemp insulation was close to its declared thermal conductivity in dynamic conditions when high relative humidity exposures were transient. In quasi steady state boundary conditions, when the insulation was allowed to reach the equilibrium moisture content at ranges of relative humidity, there was a moisture dependent increase of thermal conductivity in Hemp insulation.

Three-phase, three-limb, steady-state transformer model

This paper presents the development and implementation of a digital simulation model of a threephase, three-leg, three-winding power transformer. The proposed model, implemented in MATLAB environment, is based on the simultaneous analysis of both magnetic and electric lumped-parameters equivalents circuits, and it is intended to study its adequacy to incorporate, at a later stage, the influences of the occurrence of windings interturn short-circuit faults. Both simulation and laboratory tests results, obtained so far, for a three-phase, 6 kVA transformer, demonstrate the adequacy of the model under normal operating conditions.

Metal speciation dynamics in colloidal ligand dispersions. Part 3: Lability features of steady-state systems

A lability criterion is developed for dynamic metal binding by colloidal ligands with convective diffusion as the dominant mode of mass transport. Scanned stripping chronopotentiometric measurements of Pb(II) and Cd(II) binding by carboxylated latex core-shell particles were in good agreement with the predicted values. The dynamic features of metal ion binding by these particles illustrate that the conventional approach of assuming a smeared-out homogeneous ligand distribution overestimates the lability of a colloidal ligand system. Due to the nature of the spatial distribution of the binding sites, the change in lability of a metal species with changing ligand concentration depends on whether the ligand concentration is varied via manipulation of the pH (degree of protonation) or via the particle concentration. In the former case the local ligand density varies, whereas in the latter case it is constant. This feature provides a useful diagnostic tool for the presence of geometrically constrained binding sites.

Numerical solution of a PDE system with non-linear steady state conditions that translates the air stripping pollutants removal

This work deals with the numerical simulation of air stripping process for the pre-treatment of groundwater used in human consumption. The model established in steady state presents an exponential solution that is used, together with the Tau Method, to get a spectral approach of the solution of the system of partial differential equations associated to the model in transient state.

Spectral solution for the air stripping pollutants removal dynamic model with non linear steady state conditions

This work deals with the numerical simulation of air stripping process for the pre-treatment of groundwater used in human consumption. The model established in steady state presents an exponential solution that is used, together with the Tau Method, to get a spectral approach of the solution of the system of partial differential equations associated to the model in transient state.

Exploring the neural entrainment to musical rhythms and meter : a steady-state evoked potential approach

Thèse de doctorat réalisé en cotutelle avec l'Université catholique de Louvain, Belgique (Faculté de médecine, Institut de Neuroscience)

The Steady-State and Transient Characteristic Analysis of Thermal Fixing a Photorefractive Hologram Grating in Lithium Niobate

The transient interaction between a refraction index grating and light beams during simultaneous writing and thermal fixing of a photorefractive hologram is investigated. With a diffusion- and photovoltaic-dominated carrier transport mechanism and carrier thermal activation (temperature dependent) considered in Fe:LiNbO3 crystal, from the standpoint of field-material coupling, the theoretical thermal fixing time and the space-charge field buildup, spatial distribution, and temperature dependence are given numerically by combining the band transport model with mobile ions with the coupled-wave equation

Comparing auditory steady state response and auditory brainstem response in normal hearing adults

This paper presents a study examining auditory steady state response (ASSR) assessments compared to auditory brainstem response (ABR) assessments. The study examines the relationship between behavioral thresholds, click- and toneburst-ABR thresholds, and ASSR thresholds for normal hearing subjects using the commercially available GSI Audera instrument.

Comparing auditory steady-state response and auditory brainstem response in normal hearing adults

This paper compares the auditory steady state response (ASSR) thresholds with the click-evoked and tone burst auditory brainstem response (ABR) thresholds in their ability to predict known behavioral thresholds in normal-hearing adults.