Modified Galacto- or Fuco-Clusters Exploiting the Siderophore Pathway to Inhibit the LecA- or LecB-Associated Virulence of Pseudomonas aeruginosa

Galacto- and fuco-clusters conjugated with one to three catechol or hydroxamate motifs were synthesised to target LecA and LecB lectins of Pseudomonas aeruginosa (PA) localised in the outer membrane and inside the bacterium. The resulting glycocluster–pseudosiderophore conjugates were evaluated as Trojan horses to cross the outer membrane of PA by iron transport. The data suggest that glycoclusters with catechol moieties are able to hijack the iron transport, whereas those with hydroxamates showed strong nonspecific interactions. Mono- and tricatechol galactoclusters ( G1C and G3C ) were evaluated as inhibitors of infection by PA in comparison with the free galactocluster ( G0 ). All of them exhibited an inhibitory effect between 46 to 75 % at 100 μM, with a higher potency than G0 . This result shows that LecA localised in the outer membrane of PA is involved in the infection mechanism.     

Comparison of nonparametric methods in nonlinear mixed effects models

During the drug development, nonlinear mixed effects models are routinely used to study the drug’s pharmacokinetics and pharmacodynamics. The distribution of random effects is of special interest because it allows to describe the heterogeneity of the drug’s kinetics or dynamics in the population of individuals studied. Parametric models are widely used, but they rely on a normality assumption which may be too restrictive. In practice, this assumption is often checked using the empirical distribution of random effects’ empirical Bayes estimates. Unfortunately, when data are sparse (like in patients phase III clinical trials), this method is unreliable. In this context, nonparametric estimators of the random effects distribution are attractive. Several nonparametric methods (estimators and their associated computation algorithms) have been proposed but their use is limited. Indeed, their practical and theoretical properties are unclear and they have a reputation for being computationally expensive. Four nonparametric methods in comparison with the usual parametric method are evaluated. Statistical and computational features are reviewed and practical performances are compared in simulation studies mimicking real pharmacokinetic analyses. The nonparametric methods seemed very useful when data are sparse. On a simple pharmacokinetic model, all the nonparametric methods performed roughly equivalently. On a more challenging pharmacokinetic model, differences between the methods were clearer.     

Improving light absorption in organic solar cells by plasmonic contribution

Plasmonic phenomenon inside the materials composing an organic solar cell based on a photoactive poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylenevinylene):(6,6)-phenyl-C₆₁-butyric-acid-methyl ester (MEH-PPV:PCBM) bulk heterojunction is studied using Finite Difference Time Domain (FDTD) method calculations and the modeling results are compared with experimental results.Enhanced absorptance of light up to 50% is experimentally obtained in a 50-nm-thick blend layer including spin-coated silver nanospheres with a diameter of 40 nm. FDTD calculations based on the design of 2D-grating of nanoparticles confirm the high values of absorptance. Spatial distributions of electromagnetic field power density in the structures show confinement of the power at the interface or in the vicinity of the nanoparticles depending on the wavelength and on the preferential directions.     

Isochronism defect for various doubly rotated cut quartz resonators

It has been shown in earlier works that the amplitude-frequency effect [also called isochronism defect (ID) or anisochronism] could be a limitation factor on ultrastable oscillators. Theoretical studies based on the nonlinear theory of piezoelectricity have already been developed to explain the amplitude-frequency effect. So, it is possible to estimate the dependence of the ID versus various parameters of the resonator design (overtone rank, radius of curvature, electrodes diameter, etc.). However, because of the lack of available fourth-order elastic coefficients, it is not possible to predict the ID of any resonant frequency of a given trapped energy resonator. To tentatively find orientations of plates exhibiting a quasi- ID, we have realized electroded resonators with different orientations and curvatures. We present results that verify, particularly, the R/sup -1/2/ dependence of the amplitude-frequency effect versus radius of curvature. Moreover, we show that the ID can be positive or negative, that it can vary from one orientation to other one of about one order of magnitude, and that there exists a thermal compensated mode for which the amplitude-frequency effect is .     

Helicoidal vortex model for steady and unsteady flows

A helicoidal vortex model is used to predict the flow past the blades of a wind turbine. As the tip speed ratio (TSR) varies, the environment in which the blades operate varies, and for low enough TSR, the local angle of attack α will be larger than (α)_Clmax, the incidence of maximum lift. The problem becomes highly nonlinear and it is shown that adding an artificial viscosity term to the equation allows the iterative algorithm to converge toward a smooth solution that is physically acceptable.The introduction of unsteady effects is useful to understand the cyclic forces and moments due to yaw or tower interaction, both for the design of blades to account for fatigue and for power output prediction. The 2-D impulsively plunging plate problem is solved with a semi-implicit scheme and the integral and numerical solutions compared and shown to be in excellent agreement. A 2-D test case to study the convection of a periodic shedding of vorticity downstream of a blade element is analyzed using the same semi-implicit algorithm and a stretched mesh similar to that used to model a turbine vortex sheet. The scheme captures accurately the vorticity distribution in the wake. Finally, the scheme is applied to the simulation of the NREL two-bladed rotor in yaw to assess the validity of the approach.     

Definition of the diffusion coefficient in scattering and absorbing media

We revisit the definition of the diffusion coefficient for light transport in scattering and absorbing media. From an asymptotic analysis of the transport equation, we present a novel derivation of the diffusion coefficient, which is restricted neither to low absorption nor to a situation in which the specific intensity is quasi-isotropic. Our result agrees with previous expressions of the diffusion coefficient in the appropriate limit. Using numerical simulations, we discuss the implications of the proper choice of the diffusion coefficient for time-dependent transport.     

Fault detection and isolation in manufacturing systems with an identified discrete event model

In this article a generic method for fault detection and isolation (FDI) in manufacturing systems considered as discrete event systems (DES) is presented. The method uses an identified model of the closed-loop of plant and controller built on the basis of observed fault-free system behaviour. An identification algorithm known from literature is used to determine the fault detection model in form of a non-deterministic automaton. New results of how to parameterise this algorithm are reported. To assess the fault detection capability of an identified automaton, probabilistic measures are proposed. For fault isolation, the concept of residuals adapted for DES is used by defining appropriate set operations representing generic fault symptoms. The method is applied to a case study system.     

Status of ITER dimensional tolerance studies

The optimization of the manufacturing/assembly tolerances and processes in ITER Experimental Nuclear Fusion Device is one of the key tasks to optimize the fabrication cost, to prevent problems during assembly and to ensure that the critical homogeneity of the magnetic field and the positioning requirements of the plasma facing components can be achieved. This task is further complicated by the strong interplay among the various Tokamak systems, as for instance in the inner region of the machine where the clearances between Central Solenoid, Toroidal Field Coils, Thermal Shield, Vacuum Vessel and In-Vessel components have been minimized for their large influence on the magnetic flux and the overall machine cost.A 3D tolerance simulation analysis of ITER Tokamak machine has been developed based on 3DCS dedicated software. The dimensional variation model is representative of Tokamak functional tolerances and processes, predicting accurate values for the amount of variation on critical areas. In addition, dimensional simulations help to determine the key tolerances that contribute to a particular variation.This paper describes the current status of the Tokamak dimensional variation studies and its management plan, highlighting the status of compliance of allocated tolerances with input requirements. Management of risk issues and corrective actions are also described.     

Sensitivity of slanted fibre Bragg gratings to external refractiveindex higher than that of silica

The influence of external refractive index higher than that of silica on the transmission spectra properties of slanted fibre Bragg grating in investigated. An analytical method is presented for their potential use as refractometer for refractive index ranges beyond 1.45