110 research outputs found

    Semi-Active Suspension System Simulation Using SIMULINK

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    This paper describes a simulation design procedure aimed to achieve improved performance of the vehicle semi-active suspension. The issues related to the design of vehicle models with skyhook control are discussed. Three basic models with linear parameters are explained: quarter-, half- and full-car. The road profile is generated from a spatial power spectral density (PSD) to represent a typical road (based on ISO 8608 classification). The normalized root-mean-square values of sprung mass acceleration and tyre load forces are used to assess the vehicle ride comfort and handling performance based on five benchmark road profiles employed in industrial tests

    Practical Characterisation of the Piezo electric Properties of a 3K T300 Carbon Fibre for Impact Sensoring

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    This paper discusses the results obtained during the practical characterization of the piezo electric properties of a commonly used carbon fibre. The aim of the investigation was to prepare the grounds for the feasibility of a low cost impact sensor that could be included in any carbon fibre structure (megalithic or thin structure) without interfering the integrity of the actual structure itself. The entire measurement loop as well as the techniques of connectivity of the fibres to the loop is described within. The piezo electric effects and all factors which affect the measurements are reflected in the analysis. The results obtained shown that in normal laboratory conditions the piezo-electric response of a T300 carbon fibre is consistent and directly proportional to the impact applied to the fibre

    Genioplasty with surgical guide using 3D-printing technology : a systematic review

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    The purpose of this systematic review is to evaluate the current state of the art of making genioplasties using 3D printing technology. A multi-database single-reviewer systematic review identified sixteen papers that fulfilled the selection criteria. There were mainly case series and case reports available (Level IV of the Oxford Evidence-based medicine scale); only two prospective study (Level III) evaluated this subject. These articles are analyzed in details and summarized in this review. The realization of genioplasties with surgical guide using 3D-printing technology could improve predictability and accuracy. It protects anatomical structures in the environment of the surgery, reducing by this way the morbidity and providing safer results. The type of printer and material used as well as the sterilization techniques should be further developed by the authors. The use of open-access software should also be further explored to allow the use of these new technologies by the largest number of surgeons. Finally, prospective multi-center studies with larger samples should be performed to definitively conclude the benefits of this new technology and allow for its routine use. This article is the first systematic review on this topic

    A Test Rig for the Calibration of Strain Sensing Carbon Fibre

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    This paper presents the test equipment developed for the measurement and calibration of sensing carbon fibre. The testing device provides precise load application to a carbon fibre tow and measuring the micro-variations of the fibre electrical resistance in a temperature-controlled environment. The measurement approach based on sensing carbon fibre is a method for strain measurement being recently developed and similar to the traditional strain gauge method. However, due to the integration of the sensing element into the material, it is considered the most promising alternative for carbon fibre reinforced plastic applications. The theory behind fibre strain measurement including the influence of the temperature on the fibre electrical resistance is presented. A detailed presentation of the measurement and calibration device is given including the measurement loop. The test rig is capable of testing fibres at a temperature up to 180∘C and the maximum load applied to the fibre of 1500N . A 5-run test on a T300 3K carbon fibre at 100∘C is provided as an example of the test rig operation. On average, the accuracy of the testing method over half load (700N) offers results having a maximum variation of 5% around the mean value of the whole set of test readings collected

    Myoferlin controls mitochondrial structure and activity in pancreatic ductal adenocarcinoma, and affects tumor aggressiveness

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    Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death. Therapeutic options remain very limited and are based on classical chemotherapies. Energy metabolism reprogramming appears as an emerging hallmark of cancer and is considered a therapeutic target with considerable potential. Myoferlin, a ferlin family member protein overexpressed in PDAC, is involved in plasma membrane biology and has a tumor-promoting function. In the continuity of our previous studies, we investigated the role of myoferlin in the context of energy metabolism in PDAC. We used selected PDAC tumor samples and PDAC cell lines together with small interfering RNA technology to study the role of myoferlin in energetic metabolism. In PDAC patients, we showed that myoferlin expression is negatively correlated with overall survival and with glycolytic activity evaluated by 18F-deoxyglucose positron emission tomography. We found out that myoferlin is more abundant in lipogenic pancreatic cancer cell lines and is required to maintain a branched mitochondrial structure and a high oxidative phosphorylation activity. The observed mitochondrial fission induced by myoferlin depletion led to a decrease of cell proliferation, ATP production, and autophagy induction, thus indicating an essential role of myoferlin for PDAC cell fitness. The metabolic phenotype switch generated by myoferlin silencing could open up a new perspective in the development of therapeutic strategies, especially in the context of energy metabolism

    Lumbar spinal muscles and spinal canal study by MRI three-dimensional reconstruction in adult lumbar spinal stenosis

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    Background: Lumbar spinal stenosis is degenerative disc disease most common manifestation. If stenosisdegree seems poorly related to symptom severity, lumbar muscles role is recognized. Many studiesreport imaging methods, to analyze muscle volumes and fat infiltration (FI), but remain limited due tothe difficulty to represent entire muscle volume variability. Recently a 3D muscle reconstruction protocol(using the deformation of a parametric specific object method (DPSO) and three-point Dixon images) wasreported. It offers the ability to evaluate, muscles volumes and muscle FI.Purpose: To describe, in a lumbar spinal stenosis population, muscle volumes, muscle FI and lumbarspinal canal volume with 3D MRI images reconstructions.Materials and methods: Ten adults presenting L4–L5 lumbar stenosis, were included. After specific MRIprotocol, three-dimensional, muscle and spinal canal, reconstructions were performed. Muscle (psoasand paraspinal muscles) volumes and fat infiltration (FI), the spinal canal volume, age, and height werecorrelated one to each other with Spearman correlation factor. An ANOVA was performed to evaluate theintervertebral level influence (P ≀ 0.05).Results: Muscle volumes correlated with height (r = 0.68 for psoas). Muscles FI correlated with age (r = 0.66for psoas) and lumbar spinal canal volume (r = 0.91). Psoas and paraspinal volumes were maximum atL3–L4 level whereas FI increased from L1–L2 to L5–S1 level.Discussion: These first results illustrate the importance to consider muscles entirely and report correla-tions between muscles FI, lumbar spinal canal volume and age; and between muscle volumes and patientsheight. Muscle degeneration seems more related to muscle FI than muscle volume.Level of evidence: 3.The authors declare that they have no competing interest

    Proton MR spectroscopy and diffusion MR imaging monitoring to predict tumor response to interstitial photodynamic therapy for glioblastoma

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    International audienceDespite recent progress in conventional therapeutic approaches, the vast majority of glioblastoma recur locally, indicating that a more aggressive local therapy is required. Interstitial photodynamic therapy (iPDT) appears as a very promising and complementary approach to conventional therapies. However, an optimal fractionation scheme for iPDT remains the indispensable requirement. To achieve that major goal, we suggested following iPDT tumor response by a non-invasive imaging monitoring. Nude rats bearing intracranial glioblastoma U87MG xenografts were treated by iPDT, just after intravenous injection of AGuIXÂź nanoparticles, encapsulating PDT and imaging agents. Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) allowed us an original longitudinal follow-up of post-treatment effects to discriminate early predictive markers. We successfully used conventional MRI, T2 star (T2*), Diffusion Weighted Imaging (DWI) and MRS to extract relevant profiles on tissue cytoarchitectural alterations, local vascular disruption and metabolic information on brain tumor biology, achieving earlier assessment of tumor response. From one day post-iPDT, DWI and MRS allowed us to identify promising markers such as the Apparent Diffusion Coefficient (ADC) values, lipids, choline and myoInositol levels that led us to distinguish iPDT responders from non-responders. All these responses give us warning signs well before the tumor escapes and that the growth would be appreciated

    A quantitative genome-wide RNAi screen in C. elegans for antifungal innate immunity genes

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    OPTIMISATION COMBINATOIRE PAR ENTROPIE CROISÉE : APPLICATION À DES PROBLÈMES DE GRANDES TAILLES DANS LES ENTREPÔTS LOGISTIQUES

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    Colloque avec actes et comitĂ© de lecture. internationale.International audienceL’objectif de cette Ă©tude est de prĂ©senter la mĂ©thode de l’entropie croisĂ©e pour trouver un placement des produits performant pour un systĂšme de prĂ©paration de commandes. Ce type de problĂšme intitulĂ© SAP ou SLAP pour Storage Assignment Problem ou Storage Location Assignment Problem consiste Ă  dĂ©finir l’affectation des produits dans les diff _erentes emplacements de picking du systĂšme de prĂ©paration de commandes, sous un certain nombre de contraintes (type de support de stockage, contraintes capacitaires, foisonnement lors de la prĂ©paration, ...). Nous allons montrer que la mĂ©thode de l’entropie croisĂ©e est facilement et efficacement applicable Ă  un tel problĂšme puis nous allons d _evelopper cette mĂ©thode sur un exemple concret pour en montrer les performances
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