High performance of symmetric micro supercapacitors based on silicon nanowires using N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide as electrolyte

This work describes the development and performance of a symmetric microsupercapacitor made of nanostructured electrodes based on silicon nanowires (SiNWs) deposited using chemical vapor deposition (CVD) on silicon substrates. The performance of the SiNWs micro-supercapacitor employing an aprotic ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide) (PYR13TFSI) as an electrolyte was able to deliver a maximal power density of 182 mW cm-2 and a specific energy of 190 µJ cm-2 operating at a wide cell voltage of 4V with a quasi-ideal capacitive behaviour. The lifetime of the device exhibited a remarkable electrochemical stability retaining 75 % of the initial capacitance after several million galvanostatic charge-discharge cycles at a high current density of 1 mA cm-2. Furthermore, a coulombic efficiency of approximately 99 % was obtained after galvanostatic cycling test without structural degradation on the morphology of SiNWs

Spherical wrist dimensional synthesis adapted for tool-guidance medical robots

The objective of this article is to present the dimensional synthesis of serial or parallel spherical wrists, an important step in the design process of medical robots. This step is carried out to obtain optimal dimensions of tool-guidance medical robots. In this goal, we have first studied the specifications of two robots with different medical applications: one for minimally invasive surgery and one for tele-echography examination. Then, we have established that the medical needs expressed by the doctor were very different but the specifications in robotic terms have a lot of common points (kinematics, workspace, bulkiness). Both types of robots need a mobility of three rotations around a fixed point (trocar incision or probe contact point on patient’s skin). So a spherical wrist structure is adapted to their needs. An important constraint related to medical applications is that the robot must be compact to not obstruct the robot environment (medical personnel or patient). We perform dimensional synthesis allowing determination of dimensions of the mechanism for a spherical wrist, serial and parallel for a tele-echography robot, and serial for the minimally invasive surgery robot. We used multi-criteria optimization methods minimising a cost function to obtain both good kinematic performance and compactness for the structure. The difficulty and the difference between the presented studies are in the choice of design criteria describing the performance and the constraints of the robot. These parameters must faithfully represent the specifications of the robot so that its performance can respond to the medical requirements. We show, here, the different methods used for the chosen kinematic structure and the medical application. These studies lead to prototypes which are validated by medical experiments. This process of dimensional synthesis will be applied to other medical applications with different sets of specified constraints

Cerebellar ataxia with oculomotor apraxia type 1: clinical and genetic studies

Ataxia with ocular motor apraxia type 1 (AOA1) is an autosomal recessive cerebellar ataxia (ARCA) associated with oculomotor apraxia, hypoalbuminaemia and hypercholesterolaemia. The gene APTX, which encodes aprataxin, has been identified recently. We studied a large series of 158 families with non‐Friedreich progressive ARCA. We identified 14 patients (nine families) with five different missense or truncating mutations in the aprataxin gene (W279X, A198V, D267G, W279R, IVS5+1), four of which were new. We determined the relative frequency of AOA1 which is 5%. Mutation carriers underwent detailed neurological, neuropsychological, electrophysiological, oculographic and biological examinations, as well as brain imaging. The mean age at onset was 6.8± 4.8 years (range 2-18 years). Cerebellar ataxia with cerebellar atrophy on MRI and severe axonal sensorimotor neuropathy were present in all patients. In contrast, oculomotor apraxia (86%), hypoalbuminaemia (83%) and hypercholesterolaemia (75%) were variable. Choreic movements were frequent at onset (79%), but disappeared in the course of the disease in most cases. However, a remarkably severe and persistent choreic phenotype was associated with one of the mutations (A198V). Cognitive impairment was always present. Ocular saccade initiation was normal, but their duration was increased by the succession of multiple hypometric saccades that could clinically be confused with ‘slow saccades'. We emphasize the phenotypic variability over the course of the disease. Cerebellar ataxia and/or chorea predominate at onset, but later on they are often partially masked by severe neuropathy, which is the most typical symptom in young adults. The presence of chorea, sensorimotor neuropathy, oculomotor anomalies, biological abnormalities, cerebellar atrophy on MRI and absence of the Babinski sign can help to distinguish AOA1 from Friedreich's ataxia on a clinical basis. The frequency of chorea at onset suggests that this diagnosis should also be considered in children with chorea who do not carry the IT15 mutation responsible for Huntington's diseas

SiNWs-based electrochemical double layer micro-supercapacitors with wide voltage window (4V) and long cycling stability using a protic ionic liquid electrolyte

The present work reports the use and application of a novel protic ionic liquid (triethylammonium bis(tri fluoromethylsulfonyl)imide; NEtH TFSI) as an electrolyte for symmetric planar micro-supercapacitors based on silicon nanowire electrodes. The excellent performance of the device has been successfully demonstrated using cyclic voltammetry, galvanostatic charge-discharge cycles and electrochemical impedance spectroscopy. The electrochemical characterization of this system exhibits a wide operative voltage of 4 V as well as an outstanding long cycling stability after millions of galvanostatic cycles at a high current density of 2 mA cm. In addition, the electrochemical double layer micro-supercapacitor was able to deliver a high power density of 4 mWcm in a very short time pulses (a few ms). Our results could be of interest to develop prospective on-chip micro-supercapacitors using protic ionic liquids as electrolytes with high performance in terms of power and energy densities

The N-Terminal Domain of the Arenavirus L Protein Is an RNA Endonuclease Essential in mRNA Transcription

Arenaviridae synthesize viral mRNAs using short capped primers presumably acquired from cellular transcripts by a ‘cap-snatching’ mechanism. Here, we report the crystal structure and functional characterization of the N-terminal 196 residues (NL1) of the L protein from the prototypic arenavirus: lymphocytic choriomeningitis virus. The NL1 domain is able to bind and cleave RNA. The 2.13 Å resolution crystal structure of NL1 reveals a type II endonuclease α/β architecture similar to the N-terminal end of the influenza virus PA protein. Superimposition of both structures, mutagenesis and reverse genetics studies reveal a unique spatial arrangement of key active site residues related to the PD…(D/E)XK type II endonuclease signature sequence. We show that this endonuclease domain is conserved and active across the virus families Arenaviridae, Bunyaviridae and Orthomyxoviridae and propose that the arenavirus NL1 domain is the Arenaviridae cap-snatching endonuclease

Vertically aligned graphene nanosheets on silicon using an ionic liquid electrolyte: towards high performance on-chip micro-supercapacitors

International audienceVertically oriented graphene nanosheets were synthesized by an alternative and simple approach based on electron cyclotron resonance-plasma enhanced chemical vapor deposition (ECR-CVD) onto highly doped silicon substrates. The as-grown graphene electrodes were employed in a symmetric micro-supercapacitor using an aprotic ionic liquid [N-methyl-N-propylpyrrolidinium bis(trifluoromethyl-sulfonylimide); PYR13TFSI] as electrolyte. The device was able to deliver an outstanding specific capacitance value of 2 mF cm(-2), a power density value of 4 mW cm(-2) and an energy density value of 4 mu W h cm(-2) operating at a large and stable cell voltage of 4 V with a quasi-ideal capacitive behaviour. Moreover, the lifetime of the device exhibited a remarkable electrochemical stability retaining 80% of the initial capacitance after 150 000 galvanostatic charge-discharge cycles at a high current density of 1 mA cm(-2). This excellent electrochemical performance results from the obtained channel-based 3-D graphene network promoting rapid electrolyte ion-transport and short diffusion paths

Characterisation of pendular capillary bridges derived from experimental data using inverse problem method

International audienceIn this study we use the recent analytical model to analyze capillary interactions in liquid bridge between two spherical grains, with fixed volumes of liquid and varying separation distance. Sequences of images of capillary bridges with different parameters are recorded during experimental tests. Geometrical parameters, as contact angle, half-filling angle and neck radius, are determined by image processing. Profiles of examined bridges are approximated as a Delaunay’s roulette and superposed on recorded images. Evolution of associated variables (Laplace pressure, capillary force) is also calculated. Results of theoretical modeling are compared with the experimental ones. They match very accurately for small volumes and/or small separation distances, when influence of gravity is not significant. For larger liquid volumes and/or larger separation distances between grains the influence of the gravity is observed as a distortion (loss of symmetry) of capillary bridge. To avoid this deformation, several test were realized in micro-gravity conditions. For these tests, theoretical results are in good agreement with experimental ones, also for higher liquid volumes and/or separations distances

Theoretical and experimental study of pendular regime in unsaturated granular media

International audienceThis article addresses the experimental study of capillary bridge properties with the use of analytical calculation of bridge profile, based on solution of Young–Laplace equation. Using the measurements of some parameters as the contact angle, half-filling angle and the neck radius of the capillary bridge between two spherical particles of radius r, the shape of the bridge is estimated using theoretical solutions of Young–Laplace equation. The corresponding analytical solution is superposed and compared with image data

Supplementing Consolidation and Apportionment with anti-abuse provisions

Although it exhibits a series of interesting properties including putting an end to transfer pricing and other losses and profit distribution strategies, the allocation of cross border profits in line with international consolidation and apportionment raises some issues. One of them is the temptation for companies to locate their taxable profits outside the consolidating area, a behavior likely to ruin all the best of the system. Therefore consolidation and apportionment should be supplemented with a serious series of anti-abuse measures, especially provisions against controlled foreign companies. Those imply a revision of the taxation of foreign companies, actually a move from exemption to crediting for participating countries, and a revision of tax treaties accordingly. However, such a change, despite its economic justification, would raise several legal issues, such as its compatibility with the OECD Model and with EC Law (in the European context). The possibility of restricting this change to the sole abusive situations should be examined. Keywords: European Union, Multinational Firms, Taxation JEL: F23, H25, K3