Traitement endovasculaire des sténoses intracrâniennes (série de 27 cas pris en charge au CHU de Dijon)

DIJON-BU Médecine Pharmacie (212312103) / SudocSudocFranceF

Probabilistic Low-Rank Matrix Completion with Adaptive Spectral Regularization Algorithms

We propose a novel class of algorithms for low rank matrix completion. Our approach builds on novel penalty functions on the singular values of the low rank matrix. By exploiting a mixture model representation of this penalty, we show that a suitably chosen set of latent variables enables to derive an Expectation-Maximization algorithm to obtain a Maximum A Posteriori estimate of the completed low rank matrix. The resulting algorithm is an iterative soft-thresholded algorithm which iteratively adapts the shrinkage coefficients associated to the singular values. The algorithm is simple to implement and can scale to large matrices. We provide numerical comparisons between our approach and recent alternatives showing the interest of the proposed approach for low rank matrix completion

Complétion de matrice de rang faible probabiliste à l'aide d'algorithmes de régularisation spectrale adaptatifs

Nous proposons une nouvelle classe d'algorithmes pour la complétion de matrice de rang faible. Notre approche s'appuie sur de nouvelles fonctions de pénalité sur les valeurs singulières de la matrice de rang faible. En exploitant une représentation basée sur un modèle de mélange de cette pénalité, nous montrons qu'un ensemble de variables latentes convenablement choisi permet de dériver un algorithme EM pour obtenir une estimation du Maximum A Posteriori de la matrice de rang faible complétée. L'algorithme résultant est un algorithme à seuillage doux itératif qui adapte de manière itérative les coefficients de réduction associés aux valeurs singulières

Probabilistic Low-Rank Matrix Completion with Adaptive Spectral Regularization Algorithms

We propose a novel class of algorithms for low rank matrix completion. Our approach builds on novel penalty functions on the singular values of the low rank matrix. By exploiting a mixture model representation of this penalty, we show that a suitably chosen set of latent variables enables to derive an Expectation-Maximization algorithm to obtain a Maximum A Posteriori estimate of the completed low rank matrix. The resulting algorithm is an iterative soft-thresholded algorithm which iteratively adapts the shrinkage coefficients associated to the singular values. The algorithm is simple to implement and can scale to large matrices. We provide numerical comparisons between our approach and recent alternatives showing the interest of the proposed approach for low rank matrix completion

Impact of Mechanical Thrombectomy on the Organization of the Management of Acute Ischemic Stroke

International audienceBackground: Several trials and meta-analyses have recently demonstrated the superiority of endovascular therapy over standard medical treatment in patients presenting with acute ischemic stroke. In order to offer the best possible treatment to a maximum number of patients, many stroke care networks probably have to be reorganized. After analyzing the reliability of data in the literature, an algorithm is suggested for a pre-hospital and in-hospital alert system to improve the timeliness of subsequent treatment: a drip-and ship approach.Summary: Five recent well-designed randomized studies have demonstrated the benefit of endovascular therapy associated with intravenous fibrinolysis by recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke with confirmation by recent meta-analyses. The keys for success are a very short time to reperfusion, within 6 h, a moderate to severe pre-treatment deficit (National Institute of Health around 17), cerebral imaging able to identify proximal large vessel occlusion in the anterior circulation, a limited infarct core and a reversible penumbra, the use of the most recent devices (stent retriever) and a procedure that avoids general anesthesia, which reduces blood pressure. To meet these goals, every country must build a national stroke infrastructure plan to offer the best possible treatment to all patients eligible for intravenous fibrinolysis and endovascular therapy. The plan may include the following actions: inform the population about the first symptoms of stroke, provide the call number to improve the timeliness of treatment, increase the number of comprehensive stroke centers, link these to secondary and primary stroke centers by telemedicine, teach and train paramedics, emergency doctors and radiologists to identify the stroke infarct, proximal large vessel occlusion and the infarct core quickly, train a new generation of endovascular radiologists to improve access to this therapy. Key Message: After 20 years of rt-PA, this new evidence-based therapy is a revolution in stroke medicine that will benefit patients. However, a new robust and multi-disciplinary care strategy is necessary to transfer the scientific data into clinical practice. It will require reorganization of the stroke infrastructure, which will include comprehensive stroke centers and secondary and primary stroke centers. The winners will be patients with severe stroke

Proteasome complexes experience profound structural and functional rearrangements throughout mammalian spermatogenesis

International audienceSignificanceThe proteasome is responsible for the homeostasis of intracellular proteins. Here, we describe structural and functional aspects of a poorly characterized proteasome subtype found exclusively in germ cells. The spermatoproteasome was recently shown to be essential for spermatogenesis, a process requiring intense proteolysis. It differs from the constitutive proteasome by only one subunit, α4s, a subunit that replaces its α4 ubiquitous counterpart. In this work, we show how the shift from α4 to α4s regulates proteasome composition, dynamics, interactome, and activity. We reveal a regulation process more complex than previously suggested, which provides the basis for structural and functional studies of the spermatoproteasome

Editor's Choice – A Cost Effectiveness Analysis of Outpatient versus Inpatient Hospitalisation for Lower Extremity Arterial Disease Endovascular Revascularisation in France: A Randomised Controlled Trial

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