Jejunojejunal Intussusception After Roux-en-Y Gastric Bypass: A Review

Small bowel intussusception is a rare long-term complication after Roux-en-Y gastric bypass, the etiology of which remains unclear. Except for one series reporting on 23 patients, case reports represent the vast majority of all cases reported so far. With this complete review of the world literature, based on a total of 63 patients including 2 of our own cases, we provide an extensive overview of the subject. The origin of intussusception after gastric bypass is different from that of intussusception of other causes, in that there is usually no lead point. It is likely related to motility disorders in the divided small bowel, especially in the Roux limb. This rare condition may cause obstruction and lead to bowel necrosis if not recognized and treated promptly. Clinical presentation is not specific. Computerized tomography scan represents the diagnostic test of choice, but surgery is sometimes the only way to establish the diagnosis. Treatment may be limited to reduction if the small bowel is viable, but resection of the affected segment is recommended on the basis of this review, since it seems to result in fewer recurrences. Knowledge of this entity and a high index of suspicion are required to make the correct diagnosis and offer appropriate treatment in a timely fashio

Simplex space-time meshes in thermally coupled two-phase flow simulations of mold filling

The quality of plastic parts produced through injection molding depends on many factors. Especially during the filling stage, defects such as weld lines, burrs, or insufficient filling can occur. Numerical methods need to be employed to improve product quality by means of predicting and simulating the injection molding process. In the current work, a highly viscous incompressible non-isothermal two-phase flow is simulated, which takes place during the cavity filling. The injected melt exhibits a shear-thinning behavior, which is described by the Carreau-WLF model. Besides that, a novel discretization method is used in the context of 4D simplex space-time grids [2]. This method allows for local temporal refinement in the vicinity of, e.g., the evolving front of the melt [10]. Utilizing such an adaptive refinement can lead to locally improved numerical accuracy while maintaining the highest possible computational efficiency in the remaining of the domain. For demonstration purposes, a set of 2D and 3D benchmark cases, that involve the filling of various cavities with a distributor, are presented.Comment: 14 pages, 11 Figures, 4 Table

CIN4: A multiphysics software for heterogeneous reactions at a reactor scale

National audienceA rigorous simulation of industrial reactors in the case of solid-gas reacting systems is a complicated task due to several difficulties linked to the kinetic problem at the scale of the solid grains and to the problem of gas and heat transfers within the powder bed. Firstly it requires the knowledge of the kinetic model for the calculation of the kinetic rate of reaction in one part of the reactor and for given conditions of temperature and gas composition, and secondly it necessitates solving the material and heat balance equations for the flow conditions settled in the reactor. The first part of the article is devoted to the presentation of the kinetic models governing a population of grains transformed in the same conditions of temperature and gas composition. Then a short presentation of CIN4, a multiphysics software resulting from the collaboration between ASTEK and EMSE, shows the various scales of the calculations: CIN4 offers the resolution of the thermohydraulic equations combined with the kinetic laws which describe the heterogeneous reactions, including the diffusion aspects in the case of aggregates. Then two examples of application are given in order to illustrate the interest of this multiphysics modeling: the dehydroxylation of kaolinite and the carbonation of CaO by CO2

Deep multi-scale architectures for monocular depth estimation

This paper aims at understanding the role of multi-scale information in the estimation of depth from monocular images. More precisely, the paper investigates four different deep CNN architectures, designed to explicitly make use of multi-scale features along the network, and compare them to a state-of-the-art single-scale approach. The paper also shows that involving multi-scale features in depth estimation not only improves the performance in terms of accuracy, but also gives qualitatively better depth maps. Experiments are done on the widely used NYU Depth dataset, on which the proposed method achieves state-of-the-art performance

Development of oxidation resistant high temperature NbTiAl alloys and intermetallics

The effect of alloying elements like Ti, Al, Cr, V and Mo on the oxidation resistance of Nb at high temperature (between 700 °C and 1400 °C) has been studied. The value of the parabolic oxide growth constants, [MATH], depends on the nature and morphology of oxides formed in the external scale. The growth of protective oxides, like alumina, requires a high content of alloying elements, which usually means a lower melting point and the formation of brittle phases

MESURES LAGRANGIENNES DE GOUTTES ÉVAPORANTES DANS UNE TURBULENCE HOMOGÈNE ISOTROPE PAR HOLOGRAPHIE NUMÉRIQUE

International audienceWe present an optical technique capable of measuring 3D trajectories and size evolution of a dilute flow of droplets dispersing in a high Reynolds number turbulence, from a Lagrangian point of view. The technique used is an in-line digital holographic set-up, with an original reconstruction algorithm based on an inverse-problem approach. The experiment has been performed with water and freon droplets in a locally well defined homogeneous, nearly isotropic, turbulence. This technique allows to visualise the thermal wakes behind the droplets which are tracked

3D seismic for design and derisking of dual geothermal boreholes in sedimentary sequences and new prospects in the Paris Basin (Adapted methodology using petroleum industry techniques)

International audienceThe use of existing geological and structural maps, previous 2D seismic profiles, boreholes and correlation models between these data is sufficient to understand basin structure and thermal systems on a regional scale. However, this is not sufficient on a scale of a geothermal site to be sure of the hydraulic connectivity (or of the presence of a permeability barrier) between two boreholes 1.5 or 2 km apart.To ensure that there is enough hydraulic connectivity, it i s necessary to understand the controls on the network of fractures which affects the aquifer (fracture permeability) and the physical properties of the rock, namely the porosity and clay content in order to obtain a matrix permeability.The latest generation of broadband (six octaves) 3D seismic reflection will provide the following information: the similarity attribute will give an accurate structural map of the fault network at the seismic resolution and, in many cases, at a higher resolution than seismic; seismic velocity anisotropy analysis techniques will make it possible to visualize a 3D volume of information on the fracture network [Michel et al. (2013) Application of Azimuthal Seismic Inversion for Shale Gas Reservoir – Proceedings of the 11th SEGJ International Symposium, Yokohama]; acoustic impedance inversion or petrophysical inversion techniques will predict the porosity throughout the whole volume of the aquifer from a porosity log recorded in a pilot-hole. It allows a real 3D mapping of predicted porosity inside the aquifer much more reliably than from modelling alone.These seismic techniques were initially developed for petroleum exploration and development. They have rapidly progressed throughout the last decade, both in acquisition, processing and interpretation with new methodologies and high-performance softwares. They are efficient for modelling reservoirs to be produced.And, consequently, they can be used for geothermal applications as data to design dual deviated drillings with horizontal drains in carbonate and clastic reservoirs – not only for new projects, but also to revisit old ones to improve their performance or develop another reservoir.Broadband 3D seismic will secure the exploration of Triassic sandstones which stay an interesting prospect for deep geothermal projects.New prospects are proposed in the Paris Basin: Regional faults overlap the substratum. Inside faulted zones, hydrothermal circulations arriving by convection at the top of granitic basement could be geothermal objectives, as in the Alsace Upper Rhine Graben.A production pilot site is suggested to test superimposed aquifers and a regional fault and, at the same time, two different architectures of boreholes doublets: horizontal drains for aquifers and deviated wells for crossing a regional fault.The first site that will use this approach could be instrumented and used as an experiment with a small addition of measurements and sensors, thus becoming a showcase for geothermal energy in France. The objective of this experiment would be to determine the transit time, the heating time of the re-injected water and the circulation speed to define the optimal direction, spacing and length of drains, and also, to realize the thermal modelling of the site for different options

Investigation of heat treatment parameters effect on the microstructure and on the mechanical properties of a powder metallurgy nickel-base superalloy

International audienceThe relationships between heat treatment parameters and microstructure, and between microstructure and mechanical properties were investigated in the SMO43 disc P/M superalloy. Various heat treatments were applied to this superalloy to determine the effect of the solution temperature on the grain size, and of the cooling path and aging temperature on the ' precipitates distribution. Microstructural features were characterised through the careful study of ' precipitation. Fatigue crack growth tests with dwell time were performed at high temperature for comparison of the mechanical properties of some selected microstructures

0254: Updated reference levels for radiation doses to patients undergoing coronary angiography and coronary percutaneous interventions: the RAY’ACT2 study

PurposeThe RAY’ACT project is a nationwide, multicentre survey program aimed at evaluating patient radiation protection (RP) during coronary angiography (CA) and percutaneous coronary interventions (PCI) in French non-university public hospitals, which represent>30% of the national activity for PCIs, and 60% of the emergency cases. We present the updated reference levels based on the results of the second survey conducted in 2013 (RAY’ACT2).MethodsRP parameters from 48,547 CAs and 40,026 PCIs performed at 61 centres during 2013 and routinely registered in professional software were extracted and analysed retrospectively. Kerma-area product (KAP), fluoroscopy time (FT), number of acquired frames (Nb F) and runs (NR), and total Air Kerma at interventional reference point (KA, r) were analysed separately for CAs and PCIs (elective and ad hoc pooled). All procedures of the year were included.ResultsThe table shows the medians (Q1-Q3) of the RP parameters, updated RLs based on the 75th percentiles of the values for CA and PCI (bold), and previous RLs (RAY’ACT1, 2010).ConclusionsBetween 2010 and 2013, a 20 to 30% decrease was observed in medians and Reference Levels (Q3) for main RP parameters, including KAP and total Air Kerma.Abstract 0254 – Table: Results2013 (RAY’ACT2) 61 centres2010 (RAY’ACT1) 44 centresCAN=48,547N=31,066KAP (Gy.cm²)20.9 (11.8-35.7)27.2 (15.5-45.2)FT (min)3.3 (2.1-5.7)3.7 (2.3-6.3)Nb Frames404 (284-566)553 (388-769)KA,r (mGy)294 (164-498)421 (240-695)PCIN=40,026N=25,356KAP (Gy.cm²)45.2 (25.6-77.6)56.8 (32.8-94.6)FT (min)9.8 (6.3-15.4)10.3 (6.7-16.2)Nb Frames676 (465-960)837 (578-1193)KA,r (mGy)747 (421-1285)1052 (589-1788