Imprimantes tridimensionnelles grand public compatibles avec la dentisterie ?

The objective of this work was to define the different criteria that a general dentist will have to take into account to equip himself with a three-dimensional (3D) printer for dental use. We have identified a total of 1037 3D printers produced by 342 companies and 211 3D printers from 88 companies that can print with 25µm layers. To be able to compare them, we evaluated 16 different characteristics: 1) family of 3D printing process, 2) minimum layer thickness, 3) presence or absence of scientific study to validate the minimum layer thickness, 4) minimal resolution on XY axes, 5) type of calibration, 6) printing environment, 7) presence of a heated printing plate, 8) maximum printing speed (in mm/s) with a link giving details of the layer thickness used, the XY resolution used and the material used to determine this speed, 9) dimensions of printing capacity, 10) capacity to use materials not originating from the manufacturer, 11) capacity to use biocompatible materials, 12) weight (in kg) and printer dimensions (in cm), 13) compatible operating systems, 14) compatible 3D print file types, 15) after-sales service and warranty period, 16) price, including whether taxes are included s or not. We noted a great heterogeneity of the information present, and information often absent regarding: 1) the type of calibration, 2) the printing speed, 3) the price, 4) the after-sales service, 5) the guarantee as well as 6) the materials which are taken into account by the 3D printer. We described multiple communication difficulties with our contacts and a very dynamic development of the 3D printing world. Finally, we proposed the characteristics of an "ideal" dental 3D printer and of an "ideal" partner company for a dentist wishing to obtain the 3D printer of his choice.L’objectif de ce travail est de définir les différents critères qu’un dentiste généraliste doit prendre en compte pour s’équiper d’une imprimante tridimensionnelle (3D) à usage dentaire. Nous avons recensé au total 1037 imprimantes 3D produites par 342 entreprises et 211 imprimantes 3D de 88 entreprises pouvant imprimer avec des couches de 25µm. Pour pouvoir les comparer nous avons évalué 16 caractéristiques différentes: 1) famille de procédé d’impression 3D, 2) épaisseur de couche minimale, 3) présence ou non d’étude scientifique de validation de l’épaisseur de couche minimale, 4) résolution XY minimale, 5) type de calibrage, 6) environnement d’impression, 7) présence d’un plateau d’impression chauffant, 8) vitesse d’impression maximale (en mm/s) avec un lien donnant le détail de l’épaisseur de couche utilisée, de la résolution XY utilisée et du matériau utilisé pour déterminer cette vitesse, 9) dimensions de capacité d’impression, 10) capacité d’utiliser des matériaux ne provenant pas de l’entreprise constructrice, 11) capacité d’utiliser des matériaux biocompatibles, 12) poids (en kg) et dimensions de l’imprimante (en cm), 13) systèmes d’exploitation compatibles, 14) types de fichier d’impression 3D compatibles, 15) gestion du service après-vente et durée de la garantie, 16) prix, en indiquant si les taxes sont incluses ou non. Nous avons constaté une grande hétérogénéité des informations présentes et des informations souvent absentes en ce qui concerne : 1) le type de calibrage, 2) la vitesse d’impression, 3) le prix, 4) le service après-vente, 5) la garantie ainsi que 6) les matériaux qui sont pris en compte par l’imprimante 3D. Nous avons décrit des difficultés de communication multiples avec nos interlocuteurs et un développement très dynamique du monde d’impression 3D. Enfin, nous avons proposé des caractéristiques d’une imprimante 3D dentaire « idéale » et d’une entreprise-partenaire « idéale» pour un dentiste désireux de se procurer l’imprimante 3D de son choix

Dispersal of Egyptian Vultures Neophron percnopterus: the first case of long-distance relocation of an individual from France to Sicily.

Knowledge of juvenile dispersal is important for understanding population dynamics and for effective conservation, particularly of geographically isolated raptor populations. Here, we report the first documented case of a long-distance movement of an Egyptian Vulture Neophron percnopterus from the French population to Sicily. This observation opens a new perspective for the conservation of the small and endangered Sicilian population of this species, providing evidence that persistence of the Italian population may be aided by new input from other countries

Double di ffential fragmentation cross sections measurements of 95 MeV/u 12C on thin targets for hadrontherapy

During therapeutic treatment with heavy ions like carbon, the beam undergoes nuclear fragmentation and secondary light charged particles, in particular protons and alpha particles, are produced. To estimate the dose deposited into the tumors and the surrounding healthy tissues, an accurate prediction on the fluences of these secondary fragments is necessary. Nowadays, a very limited set of double di ffential carbon fragmentation cross sections are being measured in the energy range used in hadrontherapy (40 to 400 MeV/u). Therefore, new measurements are performed to determine the double di ffential cross section of carbon on di erent thin targets. This work describes the experimental results of an experiment performed on May 2011 at GANIL. The double di ffential cross sections and the angular distributions of secondary fragments produced in the 12C fragmentation at 95 MeV/u on thin targets (C, CH2, Al, Al2O3, Ti and PMMA) have been measured. The experimental setup will be precisely described, the systematic error study will be explained and all the experimental data will be presented.Comment: Submitted to PR

miR-143 Interferes with ERK5 Signaling, and Abrogates Prostate Cancer Progression in Mice

Abstract Background: Micro RNAs are small, non-coding, single-stranded RNAs that negatively regulate gene expression at the post-transcriptional level. Since miR-143 was found to be down-regulated in prostate cancer cells, we wanted to analyze its expression in human prostate cancer, and test the ability of miR-43 to arrest prostate cancer cell growth in vitro and in vivo. Results: Expression of miR-143 was analyzed in human prostate cancers by quantitative PCR, and by in situ hybridization. miR-143 was introduced in cancer cells in vivo by electroporation. Bioinformatics analysis and luciferase-based assays were used to determine miR-143 targets. We show in this study that miR-143 levels are inversely correlated with advanced stages of prostate cancer. Rescue of miR-143 expression in cancer cells results in the arrest of cell proliferation and the abrogation of tumor growth in mice. Furthermore, we show that the effects of miR-143 are mediated, at least in part by the inhibition of extracellular signal-regulated kinase-5 (ERK5) activity. We show here that ERK5 is a miR-143 target in prostate cancer. Conclusions: miR-143 is as a new target for prostate cancer treatment

Interaction vertex imaging (IVI) for carbon ion therapy monitoring: a feasibility study

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A large-solid-angle X-ray Raman scattering spectrometer at ID20 of the European Synchrotron Radiation Facility

An end-station for X-ray Raman scattering spectroscopy at beamline ID20 of the European Synchrotron Radiation Facility is described. This end-station is dedicated to the study of shallow core electronic excitations using non-resonant inelastic X-ray scattering. The spectrometer has 72 spherically bent analyzer crystals arranged in six modular groups of 12 analyzer crystals each for a combined maximum flexibility and large solid angle of detection. Each of the six analyzer modules houses one pixelated area detector allowing for X-ray Raman scattering based imaging and efficient separation of the desired signal from the sample and spurious scattering from the often used complicated sample environments. This new end-station provides an unprecedented instrument for X-ray Raman scattering, which is a spectroscopic tool of great interest for the study of low-energy X-ray absorption spectra in materials under insitu conditions, such as inoperando batteries and fuel cells, insitu catalytic reactions, and extreme pressure and temperature conditions.Peer reviewe

Contribution of high energy physics techniques to the medical imaging field

The purpose of this study was to show how advanced concepts of compact, lossless and "Time Of Flight" (TOF) capable electronics similar to those foreseen for the LHC and ILC experiments could be fairly and easily transferred to the medical imaging field through Positron Emission Tomography (PET). As a wish of explanation, the two overriding weaknesses of PET camera readout electronics, namely dead-time and timing resolution, were investigated analytically and with a Monte-Carlo simulator presently dedicated to this task. Results have shown there was room left for count rate enhancement through a huge decrease of the timing resolution well below the nanosecond. The novel electronics scheme suggested for PET in this paper has been partly inspired by the long experience led in High Energy Physics where the latter requirement is compulsory. Its structure entirely pipelined combined to a pixelation of the whole detector should allow dead-times to be suppressed, while the absence of devoted timing channel would remove the preponderant contributions to the timing resolution. To the common solution for timing would substitute an optimal filtering method witch clearly appears as a good candidate as timing resolution of a few tens of picoseconds may be achieved provided the shape of the signal is known and sufficient samples are available with enough accuracy. First investigations have yield encouraging results as a sampling frequency of 50 MHz with a 7 bits precision appears sufficient to ensure the 500ps coincidence timing resolution planed. At this point, there will be a baby step ahead to draw benefice from a TOF implementation to the design and the enormous noise variance enhancement that would come with.Comment: presented at EuroMedIm 2006 : 1st European Conference on Molecular Imaging Technology, Marseille 9-12 May 2006, 6 pp, 4 figures, submitted to NI

Real time monitoring of the Bragg-peak position in ion therapy by means of single photon detection

For real-time monitoring of the longitudinal position of the Bragg-peak during an ion therapy treatment, a novel non-invasive technique has been recently proposed that exploits the detection of prompt -rays issued from nuclear fragmentation. Two series of experiments have been performed at the GANIL and GSI facilities with 95 MeV/u and 305 MeV/u 12C6+ ion beams stopped in PMMA and water phantoms. In both experiments a clear correlation was obtained between the carbon ion range and the prompt photon profile. Additionally, an extensive study has been performed to investigate whether a prompt neutron component may be correlated with the carbon ion range. No such correlation was found. The present paper demonstrates that a collimated set-up can be used to detect single photons by means of time-of-flight measurements, at those high energies typical for ion therapy. Moreover, the applicability of the technique both at cyclotron and synchrotron facilities is shown. It is concluded that the detected photon count rates provide sufficiently high statistics to allow real-time control of the longitudinal position of the Bragg-peak under clinical conditions

Comparison of two analysis methods for nuclear reaction measurements of 12C +12C interactions at 95 MeV/u for hadrontherapy

During therapeutic treatment with heavier ions like carbon, the beam undergoes nuclear fragmentation and secondary light charged particles, in particular protons and alpha particles, are produced. To estimate the dose deposited into the tumors and the surrounding healthy tissues, the accuracy must be higher than ($\pm$3% and$\pm$1 mm). Therefore, measurements are performed to determine the double differential cross section for different reactions. In this paper, the analysis of data from 12C +12C reactions at 95 MeV/u are presented. The emitted particles are detected with \DeltaEthin-\DeltaEthick-E telescopes made of a stack of two silicon detectors and a CsI crystal. Two different methods are used to identify the particles. One is based on graphical cuts onto the \DeltaE-E maps, the second is based on the so-called KaliVeda method using a functional description of \DeltaE versus E. The results of the two methods will be presented in this paper as well as the comparison between both