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To observe hyperechoic nodular or punctate white matter lesions (HNPL) in a population of preterm infants using routine cranial ultrasound (cUS), to describe the characteristics of HNPL, and to compare them with punctate white matter lesions (PWML) detected in magnetic resonance imaging (MRI). Retrospective observational single-center cohort study. Level 2B neonatal unit in France. 307 infants born <33 weeks gestation undergoing routine cUS with a total of 961 cUS performed. Description of lesions (HNPL/PWML): presence or absence, number, size, location, and structural distribution. Among the 307 included infants, 63 (20.5%) had at least one cerebral lesion, with 453 HNPL for 63 infants. HNPL were numerous (more than three in 66.6% of cases), primarily grouped in clusters (76.2%), located near the lateral ventricles (96.8%), and measuring more than 2 mm (79%). HNPL were diagnosed on day 29 on average and persisted until term. Overall, 43 MRI were performed in 307 infants, on average 18.9 days after last cUS, in 21 of those the indication was presence of HPNL on cUS. Of these 21 MRI, 14/21 presented 118 PWML compared to 173 HNPL on cUS. In the remaining MRI (7/21), no PWML were detected compared to 47 HNPL on cUS. In our population of 307 preterm infants, cUS allowed the diagnosis of HNPL, with a large similarity to PWML in MRI and a better sensitivity. But in the absence of data on inter-observer variability, we cannot exclude overdiagnosis of HNPL. • PWML are frequently seen on cUS and MRI in premature infants. • PWML are not easily diagnosed on cUS. • This work describes for the first time WM hyperechoic lesions on cUS similar to PWML. • Diagnosis of these lesions could be extended to all preterm infants with cUS3D and IA. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2007.10.023 Byline: Sandrine Meresse (a), Francois Costard (a), Nicolas Mangold (a), Philippe Masson (a), Gerhard Neukum (b) Keywords: Mars; surface; Geological processes; Volcanism Abstract: The origin of the martian chaotic terrains is still uncertain; and a variety of geologic scenarios have been proposed. We provide topographic profiles of different chaos landscapes, notably Aureum and Hydraotes Chaos, showing that an initial shallow ground subsidence occurred at the first step of the chaos formation. We infer that the subsidence was caused by intrusion of a volcanic sill; which could have produced consequent melting as well as release of ground water from disrupted aquifer. Signs of a volcanic activity are observed on the floor of Hydraotes Chaos, a complex and deep depression located at the junction of three channels. The volcanic activity is represented by small, 0.5 to 1.5 km diameter, rounded cones with summit pits. The cone's size and morphology, as well as the presence of possible surrounding lava flows, suggest that they are primary volcanic cones similar to terrestrial cinder cones. The identification of volcanic activity on the deepest chaos, where the lower crustal thickness and the faults/fractures system contributed to the magma rising, reveals that magmatic activity, proved by the cones, and possibly help by structural activity, has been a major factor in the formation of chaotic terrains. Author Affiliation: (a) Laboratoire IDES, UMR 8148, Universite Paris-Sud 11, BAcentst 509, 91405 Orsay cedex, France (b) Institut fur Geologische Wissenschaften, Freien Universitat, Berlin, Germany Article History: Received 5 July 2007; Revised 25 September 2007

The work presented in this paper relates to the optimization of operating parameters of the welding by the experimental design approach. The welding process used is the hybrid laser-MAG welding, which consists in combining a laser beam with an MAG torch, to increase the productivity and reliability of the chamfer filling operation in several passes over the entire height of the chamfer. Each pass, providing 2 mm deposited metal and must provide sufficient lateral penetration of about 0.2 mm. The experimental design method has been used in order to estimate the operating parameters effects and their interactions on the lateral penetration on one hand, and to provide a mathematical model that relates the welding parameters of welding to the objective function lateral penetration on the other hand. Furthermore, in this study, we sought to the identification of the set of optimum parameters sufficient to comply with a constraint on the quality of weld bead. This constraint is to simultaneously obtain a total lateral penetration greater than 0.4 mm and an H/L ratio less than 0.6. In order to obtain this condition, the multi-objective optimization (for both response functions) of a weld bead by the implementation of the plans method using two categories of Experiments Plans, on two levels has been used: the first is a complete experimental design (CED) with 32 tests and the second a fractional experimental design (FED) with 8 tests. A comparative analysis of the implementation of both types of experiments plans identified the advantages and disadvantages for each type of plan. [ABSTRACT FROM AUTHOR]

Abstract: The present work deals with the estimation of the time evolution of the weld fusion boundary. This moving boundary is the result of a spot GTA welding process on a 316L stainless steel disk. The estimation is based on the iterative regularization method. Indeed, the three problems: direct, in variation and adjoint, classically associated with this method, are solved by the finite element method in a two-dimensional axisymmetric domain. The originality of this work is to treat an experimental estimation of a front motion using a model with a geometry including only the solid phase. In this model, the evolution of this solid domain during the fusion is set with the ALE moving mesh method (Arbitrary Lagrangian Eulerian). The numerical developments are realized with the commercial code Comsol Multiphysics ® coupled with the software Matlab ®. The estimation method has been validated in a previous work using theoretical data ([1]). The experimental data, used here for this identification are, temperatures measured by thermocouples in the solid phase, the temporal evolution of the melt pool boundary observed at the surface by a fast camera and the maximal dimensions of the melted zone measured on macrographs. These experimental data are also compared with numerical results obtained from a heat and fluid flow model taking into account surface tension effects, Lorentz forces and the deformation of the melt pool surface under arc pressure. [Copyright &y& Elsevier]

Abstract: This paper deals with heat transfer analysis in a static welding process. A method is developed to estimate the evolution of a 2D axisymmetric shape of a fusion front. The estimation is performed from theoretical temperature measurements taken in the solid part from a multiphysics problem which is validated with an experiment. The estimation procedure is based on the conjugate gradient method coupled with the iterative regularization algorithm. The gradient is computed using adjoint equations. The goal of this work is to apply an ALE (Arbitrary Lagrangian Eulerian) moving mesh method suitable for solving two-dimensional and axisymmetric moving-boundary problems. Owing to the calculation of the fluid flow inside the melt pool, the definition and the resolution of the multiphysics problem are very difficult (unknown phenomena and computation time). Thus a simplified problem, without the liquid zone, is developed. This means that at each time increment, the domain is modeled considering the fusion of the material and the shape is estimated by an inverse method. [Copyright &y& Elsevier]

A numerical method for the two-dimensional estimation of a convection heat transfer coefficient is developped for a rapid metallurgical heat treatment: the “Jominy end-quench” test. The estimation algorithm is based on the iterative regularization method and on the conjugate gradient and adjoint methods. The procedure is verified for two different materials. The first material, the Nickel, has no metallurgic transformation. The second one, the 16MND5 steel, has transformations implying high nonlinearities in the material. The estimation is simulated numerically for three types of heat transfer coefficients and theoritical thermal cycles. One of these coefficients can be brought together with an experimental case. For the noised thermal cycles the solution is stabilized by the iterative regularization. [Copyright &y& Elsevier]

• Flash method with laser heating and flux measurements with a pyrometer is proposed. • Thermal properties of a levitating metal sample are obtained via Bayesian Inversion. • Sources of inaccuracies/uncertainties of the auxiliary parameters are accounted for. • An Analytical solution for a reduced heat conduction model is developed. • Model reduction errors are also accounted for, through the approximation error model. The flash method has been the standard technique for the measurement of thermal diffusivity since it was first developed by Parker and co-workers. Several modifications of the original method have been proposed in the literature, to deal with different physical situations and materials. In this work, we extend the front-face flash method for the simultaneous estimation of the thermal diffusivity and thermal conductivity of aerodynamically levitated spherical solid metal samples at high temperatures, with laser excitation and contactless temperature measurements taken with a pyrometer. The mathematical model associated to the physical problem is formulated as an axisymmetric heat conduction problem, with heat losses by radiation and convection. Since the measurements of a pyrometer are in fact radiative fluxes, the transfer function of the pyrometer is integrated in the mathematical model. A sensitivity analysis is performed and reveals that the thermal diffusivity and the thermal conductivity of the sample can be simultaneously estimated, provided that the other model parameters are known. The solution of the inverse problem is obtained with algorithms within the Bayesian framework of statistics, by using a heat conduction reduced model with linear boundary conditions, for which an analytical solution is developed for fast computations. The Bayesian Approximation Error Model is used to compensate for errors between a complete heat conduction model with nonlinear boundary conditions and a reduced heat conduction model with linear boundary conditions. Moreover, errors related to the inaccuracy and the uncertainties of all model parameters are accounted for in the inverse analysis. Simulated transient flux measurements are assumed available from a multi-spectral pyrometer and are used for the inverse problem solution. [ABSTRACT FROM AUTHOR]

A high-throughput screen against Inventiva's compound library using a Gal4/RORγ-LBD luciferase reporter gene assay led to the discovery of a new series of quinoline sulphonamides as RORγ inhibitors, eventually giving rise to a lead compound having an interesting in vivo profile after oral administration. This lead was evaluated in a target engagement model in mouse, where it reduced IL-17 cytokine production after immune challenge. It also proved to be active in a multiple sclerosis model (EAE) where it reduced the disease score. The synthesis, structure activity relationship (SAR) and biological activity of these derivatives is described herein. [ABSTRACT FROM AUTHOR]

Background: We investigated whether the health-related quality of life (HRQoL) score is a prognostic factor for overall survival (OS) in elderly patients with advanced nonsmall-cell lung cancer (NSCLC). Methods: We included 451 NSCLC patients aged 70-89 years enrolled in the Intergroupe Francophone de Cancérologie Thoracique 0501 trial, using scores of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 at baseline to investigate the prognostic value of HRQoL for OS, in addition to conventional factors. Cox regression model was used for both univariate and multivariate analyses of OS. Results: Global health status (GH) dimension score at baseline was associated with favourable OS when adjusted for clinical, functional, and histological factors (hazard ratio [HR]: 0.986; 95% confidence interval [CI]: 0.980-0.992). We distinguished three groups according to GH score: high (GH <46), intermediate (46 ≤GH ≤67), and low (GH >67) mortality risk. The median OS values were 14.5, 8.2, and 5.3 months in the low-, intermediate-, and high-risk categories, respectively (log-rank P <0.0001). In the high-risk group, doublet chemotherapy was not associated with favourable OS (HR: 0.70; 95% CI: 0.49-1.003; P=0.052), whereas in the intermediate- and low-risk groups, doublet chemotherapy was associated with favourable OS (HR: 0.72; 95% CI: 0.54-0230.96; P=0.023 and HR: 0.50; 95% CI: 0.30-0.84; P=0.0089, respectively). Conclusion: This study supports the additional prognostic value of HRQoL data at diagnosis to identify vulnerable subpopulations in elderly NSCLC patients. HRQoL could thus be valuable in selecting patients who will benefit from doublet chemotherapy. [ABSTRACT FROM AUTHOR]

Unintended evaporation of additive elements can be observed on alloys during processes involving high temperatures and fusion. Indeed, welding, casting and additive manufacturing of steels lead to temperatures sufficiently high to start the evaporation of some low boiling point element such as manganese. In this paper, both experimental and numerical approaches are developed to study and quantify this phenomenon. Experimentally, an ex-situ aerodynamic levitation apparatus is employed to apply varying temperatures or durations at liquid state to a 304L steel sample. These experiments are represented numerically with a multiphysics model solving heat transfer, fluid flow and evolution of concentration of manganese dynamically. Equations chosen to represent this poorly studied phenomena are presented and compared to experiments. A comparison highlights a good accuracy of the proposed model. This precision increases particularly when the melting duration is high. Order of magnitude of evaporation phenomena is precisely quantified with time and temperature dependencies. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: While hybrid laser welding and coating processes involve a large number of physical phenomena, it is currently impossible to predict, for a given set of influencing factors, the shape of the molten zone and the history of temperature fields inside the parts. This remains true for complex processes, such as the hybrid laser/MIG welding process, which consists in combining a laser beam with a MIG torch. The gains obtained result essentially from the synergy of the associated processes: the stability of the process, the quality of the seam realized, and the productivity are increased. This article shows how, by means of a reduced number of experiments (8), it is possible to predict the shape of the molten zone and the temperature field inside parts, for a given window of influencing factors. This method consists in combining the method of exploratory experimental designs with a numerical modelling of the thermal phenomena that occurs during the process, by using the ‘heat equivalent source” approach . Two validations of this method have been carried out: the first for a set of parameters inside the experimental design, and the other for a set of parameters that lies outside the experimental design, but inside the domain investigated. [ABSTRACT FROM AUTHOR]

Abstract: A three-dimensional heat transfer model was developed to predict the temperature fields, the weld geometry and the shape of the solidified weld reinforcement surface during hybrid laser-MAG arc welding of fillet joints. Melt pool deformation due to arc pressure was calculated by minimizing the total surface energy. A series of hybrid welding experiments was conducted on S355 steel for different welding speeds and wire feeding rates. A high speed video camera was used to measure weld pool depression and surface weld pool geometry. Visualization of the weld pool during welding has also allowed for a better understanding of the interaction between the keyhole and droplets. The various weld bead shapes were explained through these observations. The arc pressure, the surface energy distribution, and arc efficiency were evaluated by comparing experimental data and numerical results for a wide range of welding operating parameters. Good correlation was found between the calculated and experimental weld bead shapes obtained for the hybrid laser-MAG arc welding process as well as for laser or MAG alone. [ABSTRACT FROM AUTHOR]

• The temperature and the emissivity of niobium and steel are estimated around their melting points by multispectral pyrometry. • The experimental data are radiative fluxes collected by a six-wavelength pyrometer and by a commercial bichromatic pyrometer. • The apparatus is dedicated to the characterization of the physical properties of millimeter-size metal samples at high temperatures, combining aerodynamic levitation and laser heating. • Different techniques are used are based on deterministic (ordinary least squares) and Bayesian approaches. This article presents the temperature and emissivity estimation of metals around their melting points using different techniques, which are based on deterministic (ordinary least squares) and Bayesian approaches. Linear and non-linear models are examined. The experimental data consist of radiative fluxes at six wavelengths, collected by a pyrometer. The apparatus is dedicated to the characterization of the physical properties of millimeter-sized metal samples at high temperatures, combining aerodynamic levitation and laser heating. Tests are performed on two metals: niobium with well-known temperature and steel. [ABSTRACT FROM AUTHOR]