219 research outputs found

    Two load sharing plates fixation in mandibular condylar fractures: Biomechanical basis

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    Mandibular condylar fractures have a high incidence but there is no consensus regarding the best choice of osteosynthesis. From a review of the literature, it is evident that the technique used most frequently for fixation is the positioning of a single plate despite complications concerning plate fracture or screw loosening have been reported by various authors. Different studies have highlighted that the stability of osteosynthesis is correlated with the mechanical strains occurring in the condylar region, generated by the muscles of mastication. The aim of our study was, through a mandibular finite element model (FEM), to confirm this correlation and to analyse the behaviour of single and double elements of union in the fixation of mandibular subcondylar fractures. We concluded that the use of two plates provides greater stability compared with the single plate, reducing the possibility of displacement of the condylar fragment. Therefore we recommend that this technique should be adopted whenever possible

    Extracellular Superoxide Dismutase Expression in Papillary Thyroid Cancer Mesenchymal Stem/Stromal Cells Modulates Cancer Cell Growth and Migration

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    Tumor stroma-secreted growth factors, cytokines, and reactive oxygen species (ROS) influence tumor development from early stages to the metastasis phase. Previous studies have demonstrated downregulation of ROS-producing extracellular superoxide dismutase (SOD3) in thyroid cancer cell lines although according to recent data, the expression of SOD3 at physiological levels stimulates normal and cancer cell proliferation. Therefore, to analyze the expression of SOD3 in tumor stroma, we characterized stromal cells from the thyroid. We report mutually exclusive desmoplasia and inflammation in papillary and follicular thyroid cancers and the presence of multipotent mesenchymal stem/stromal cells (MSCs) in non-carcinogenic thyroids and papillary thyroid cancer (PTC). The phenotypic and differentiation characteristics of Thyroid MSCs and PTC MSCs were comparable with bone marrow MSCs. A molecular level analysis showed increased FIBROBLAST ACTIVATING PROTEIN, COLLAGEN 1 TYPE A1, TENASCIN, and SOD3 expression in PTC MSCs compared to Thyroid MSCs, suggesting the presence of MSCs with a fibrotic fingerprint in papillary thyroid cancer tumors and the autocrine-paracrine conversion of SOD3 expression, which was enhanced by cancer cells. Stromal SOD3 had a stimulatory effect on cancer cell growth and an inhibitory effect on cancer cell migration, thus indicating that SOD3 might be a novel player in thyroid tumor stroma

    3D segmentation of intervertebral discs: from concept to the fabrication of patient-specific scaffolds

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    Aim: To develop a methodology for producing patient-specific scaffolds that mimic the annulus fibrosus (AF) of the human intervertebral disc (IVD) by means of combining magnetic resonance imaging (MRI) and 3D bioprinting. Methods: In order to obtain the AF 3D model from patientâ s volumetric MRI dataset, the RheumaSCORE segmentation software was used. Polycaprolactone scaffolds with three different internal architectures were fabricated by 3D bioprinting, and characterized by micro-computed tomography. Results: The demonstrated methodology of a geometry reconstruction pipeline enabled to successfully obtain an accurate AF model and 3D print patient-specific scaffolds with different internal architectures. Conclusion: The results guide us towards patient-specific IVD tissue engineering as demonstrated a way of manufacturing personalized scaffolds using patient's MRI data.The authors would like to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAPEXPL/BBB-ECT/0050/2014), funded in the Framework of the ‘International Collaboratory for Emerging Technologies, CoLab’, UT justin|Portugal Program. FCT is also acknowledged for the PhD scholarship attributed to IF Cengiz (SFRH/ BD/99555/2014) and the financial support provided to J Silva-Correia (SFRH/BPD/100590/2014 and IF/00115/2015). JM Oliveira also thanks the FCT for the funds provided under the program Investigador FCT (IF/00423/2012 and IF/01285/2015). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.info:eu-repo/semantics/publishedVersio

    Electronics design of the RPC system for the OPERA muon spectrometer

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    The present document describes the front-end electronics of the RPC system that instruments the magnet muon spectrometer of the OPERA experiment. The main task of the OPERA spectrometer is to provide particle tracking information for muon identification and simplify the matching between the Precision Trackers. As no trigger has been foreseen for the experiment, the spectrometer electronics must be self-triggered with single-plane readout capability. Moreover, precision time information must be added within each event frame for off-line reconstruction. The read-out electronics is made of three different stages: the Front-End Boards (FEBs) system, the Controller Boards (CBs) system and the Trigger Boards(TBs) system. The FEB system provides discrimination of the strip incoming signals; a FAST-OR output of the input signals is also available for trigger plane signal generation. FEB signals are acquired by the CB system that provides the zero suppression and manages the communication to the DAQ and Slow Control. A Trigger Board allows to operate in both self-trigger mode (the FEB’s FAST-OR signal starts the plane acquisition) or in external-trigger mode (different conditions can be set on the FAST-OR signals generated from different planes)

    The MU-RAY project: Volcano radiography with cosmic-ray muons

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    Cosmic-ray muon radiography is a technique for imaging the variation of density inside the top few 100m of a volcanic cone. With resolutions up to 10s of meters in optimal detection conditions, muon radiography can provide images of the top region of a volcano edifice with a resolution that is considerably better than that typically achieved with conventional methods. Such precise measurements are expected to provide us with information on anomalies in the rock density distribution, like those expected from dense lava conduits, low density magma supply paths or the compression with depth of the overlying soil. The MU-RAY project aims at the construction of muon telescopes and the development of new analysis tools for muon radiography. The telescopes are required to be able to work in harsh environment and to have low power consumption, good angular and time resolutions, large active area and modularity. The telescope consists of two X–Y planes of 2x2 square meters area made by plastic scintillator strips of triangular shape. Each strip is read by a fast WLS fiber coupled to a silicon photomultiplier. The readout electronics is based on the SPIROC chip.Published120-1231.4. TTC - Sorveglianza sismologica delle aree vulcaniche attiveJCR Journalrestricte

    LATEST DEVELOPMENTS ON MICROMORPH TANDEM CELLS AT IMT

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    The latest developments on micromorph tandem cells in small area laboratory and large area industrial PE-CVD systems are reviewed. We report on a 13.3% initial efficiency micromorph tandem cell deposited in our small area system. The development of an in-situ silicon oxide based intermediate reflector layer (SOIR) was essential in order to achieve such high efficiencies. We describe its detailed material structure and discuss optical management aspects for different cell configurations. In our large area industrial R&D reactor the highest efficiency so far obtained is a 11.0% initial efficiency micromorph tandem cell. We discuss in detail the role of pressure and silane depletion on the cell parameters of single junction microcrystalline cells and present efficiency trends decreasing from 8.2% to 7.0% with deposition rates increasing from 0.3 nm/s to 1.2 nm/s

    Study of the threshold anomaly effect in the reaction 7 Li+ 208 Pb at energies around the Coulomb barrier

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    The elastic scattering in the reaction7Li+208Pb was investigated in the bombarding energy range from 25 to39 MeV. The real and imaginary parts of the optical potential were analyzed by using a phenomenological potential. A dispersion relation analysis is presented in order to investigate the threshold anomaly effect. It is concluded that7Li has an intermediate behavior between the tightly bound nuclei suchas16O and the loosely bound nuclei such as6Li where the lack of the threshold anomaly is unambiguously observed.Reaction cross sections are also extracted from the elastic scattering data and its comparison with the ones of other systems has been performed to draw hints on the effect of the breakup channel

    The trigger system of the ICARUS experiment

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    This paper presents the hardware architecture and the main features of the ICARUS trigger system. The ICARUS detector is a very massive liquid Argon Time Projection Chamber aimed at the study of some of the fundamental issues of astroparticle physics such as solar and atmospheric neutrino interactions, neutrinos following a supernova explosion, neutrino oscillations with beams from particle accelerator, nucleon decay for some channels predicted by GUTs. The main feature of the proposed trigger design is its "segmentation", i.e. the capability to trigger different sectors of the detector on different events allowing for the efficient detection of rare event

    The Treiman-Yang Criterion: validating the Trojan Horse Method by experimentally probing the reaction mechanism

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    Proper selection of the quasi-free (QF) break-up channel in a three-body reaction is a key aspect for the applicability of the Trojan Horse Method (THM). The Treiman-Yang (TY) Criterion is a model-independent experimental test for the dominance of the QF mechanism, and hence constitutes one of the strongest validity tests of the THM. An experiment was performed at LNS to apply the test to the d(10B, 7Be α)n reaction. Here, the criterion is described and some preliminary data from the experiment are shown

    Research and developments in thin film silicon photovoltaics

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    The increasing demand for photovoltaic devices and the associated crystalline silicon feedstock demand scenario have led in the past years to the fast growth of the thin film silicon industry. The high potential for cost reduction and the suitability for building integration have initiated both industrial and research laboratories dynamisms for amorphous silicon and micro-crystalline silicon based photovoltaic technologies. The recent progress towards higher efficiencies thin film silicon solar cells obtained at the IMT-EPFL in Neuchatel in small-area laboratory and semi-large-area industrial Plasma Enhanced Chemical Vapor Deposition (PE-CVD) systems are reviewed. Advanced light trapping schemes are fundamental to reach high conversion efficiency and the potential of advanced Transparent Conductive Oxides (TCO) is presented, together with issues associated to the impact of the substrate morphology onto the growth of the silicon films. The recent improvements realized in amorphous-microcrystalline tandem solar cells on glass substrate are then presented, and the latest results on 1 cm2 cells are reported with up to 13.3 % initial efficiency for small-area reactors and up to 12.3 % initial for large-area industrial reactors. Finally, the different strategies to reach an improved light confinement in a thin film solar cell deposited on a flexible substrate are discussed, with the incorporation of asymmetric intermediate reflectors. Results of micromorph solar cells in the n-i-p configuration with up to 9.8 % stabilized efficiency are reported
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