Une etiologie rare d’une ulceration palatine : la sialometaplasie necrosante

La sialométaplasie nécrosante (SN) est une affection salivaire bénigne et rare, touchant principalement les glandes salivaires palatines et présentant des ressemblances cliniques et histologiques avec les carcinomes orales. Nous rapportons un cas de SN chez une patiente de 73 ans, non tarée, édentée, qui rapporte la notion de prothèse ancienne mal adaptée et qui présente une lésion ulcéro-végétante, bien limitée, douloureuse, palatine gauche, évoluant depuis 3 mois. Le scanner du massif facial a montré un épaississement des parties molles palatines avec un aspect aminci et irrégulier de l’os en regard. Une pathologie maligne à type de carcinome muco-épidermoide a été évoquée. Une exérèse radicale de la lésion a été réalisée et l’examen histologique a conclu à une SN.Mots clés : Sialométaplasie nécrosante; orale; palais; histologieNecrotizing sialometaplasia (NS) is a relatively uncommon benign disease of the salivary glands that most commonly occurs in the palate. It is often confused clinically and histopathologically with malignancies, such as squamous cell carcinoma or mucoepidermoid carcinoma. We report a case of NS in an edentate 73-year-old woman, with no medical history, showed up with a painful, well limited ulcerative lesion on the left palate, reporting its appearance three months ago. Reported also that she had a badly adapted removable denture. CT scan showed a thickening of the palate’s soft tissues with bone irregularity and thinning. A mucoepidermoid carcinoma was suspected. The patient underwent a radical excision of the lesion and histopathological diagnosis of NS was made.Keywords: Necrotizing sialometaplasia; oral; palate; histolog

Kyste thymique cervical

Objectifs : Le kyste thymique est une tumeur congénitale rare. Souvent asymptomatique, elle atteint généralement les enfants âgés de moins de 10 ans. Siégeant au niveau du cou, cette tumeur pose essentiellement le problème de diagnostic différentiel clinique. Son traitement est chirurgical avec un excellent pronostic et un très faible risque de récidive locale. Nous rapportons un cas de kyste thymique cervical et nous rappelons la pathogénie et les diagnostics différentiels.Mots clés : kyste thymique, cou, histologiePurpose of study: The thymic cyst is a rare congenital tumor. Usually asymptomatic, this tumor is generally seen in childhood under the age of ten. In the neck, the preoperative diagnosis of this tumor is difficult and is rarely made. The treatment of choice is surgical excision. The long-term prognosis is excellent with a low rate of local recurrence. We report a new case of cervical thymic cyst and review the pathogenesis and the differential diagnosis.Keywords: Thymic cyst, neck, histology

On the unsteady behavior of turbulence models

Periodically forced turbulence is used as a test case to evaluate the predictions of two-equation and multiple-scale turbulence models in unsteady flows. The limitations of the two-equation model are shown to originate in the basic assumption of spectral equilibrium. A multiple-scale model based on a picture of stepwise energy cascade overcomes some of these limitations, but the absence of nonlocal interactions proves to lead to poor predictions of the time variation of the dissipation rate. A new multiple-scale model that includes nonlocal interactions is proposed and shown to reproduce the main features of the frequency response correctly

Redundantly Amplified Information Suppresses Quantum Correlations in Many-Body Systems

We establish bounds on quantum correlations in many-body systems. They reveal what sort of information about a quantum system can be simultaneously recorded in different parts of its environment. Specifically, independent agents who monitor environment fragments can eavesdrop only on amplified and redundantly disseminated - hence, effectively classical - information about the decoherence-resistant pointer observable. We also show that the emergence of classical objectivity is signaled by a distinctive scaling of the conditional mutual information, bypassing hard numerical optimizations. Our results validate the core idea of Quantum Darwinism: objective classical reality does not need to be postulated and is not accidental, but rather a compelling emergent feature of quantum theory that otherwise - in absence of decoherence and amplification - leads to "quantum weirdness". In particular, a lack of consensus between agents that access environment fragments is bounded by the information deficit, a measure of the incompleteness of the information about the system.Comment: LA-UR-21-2994

Eavesdropping on the Decohering Environment: Quantum Darwinism, Amplification, and the Origin of Objective Classical Reality

"How much information about a system $\mathcal{S}$ can one extract from a fragment $\mathcal{F}$ of the environment $\mathcal{E}$ that decohered it?" is the central question of Quantum Darwinism. To date, most answers relied on the quantum mutual information of $\mathcal{SF}$, or on the data extracted by measuring $\mathcal{S}$ directly. These are reasonable upper bounds on what is really needed but much harder to calculate -- the channel capacity of the fragment $\mathcal{F}$ for the information about $\mathcal{S}$. We consider a model based on imperfect c-not gates where all the above can be computed, and discuss its implications for the emergence of objective classical reality. We find that all relevant quantities, such as the quantum mutual information as well as the channel capacity exhibit similar behavior. In the regime relevant for the emergence of objective classical reality this includes scaling independent from the quality of the imperfect c-not gates or the size of $\mathcal{E}$, and even nearly independent of the initial state of $\mathcal{S}$.Comment: 7+6 pages, 5 figure

Decay of scalar variance in isotropic turbulence in a bounded domain

The decay of scalar variance in isotropic turbulence in a bounded domain is investigated. Extending the study of Touil, Bertoglio and Shao (2002; Journal of Turbulence, 03, 49) to the case of a passive scalar, the effect of the finite size of the domain on the lengthscales of turbulent eddies and scalar structures is studied by truncating the infrared range of the wavenumber spectra. Analytical arguments based on a simple model for the spectral distributions show that the decay exponent for the variance of scalar fluctuations is proportional to the ratio of the Kolmogorov constant to the Corrsin-Obukhov constant. This result is verified by closure calculations in which the Corrsin-Obukhov constant is artificially varied. Large-eddy simulations provide support to the results and give an estimation of the value of the decay exponent and of the scalar to velocity time scale ratio

The decay of homogeneous anisotropic turbulence

We present the results of a numerical investigation of three-dimensional decaying turbulence with statistically homogeneous and anisotropic initial conditions. We show that at large times, in the inertial range of scales: (i) isotropic velocity fluctuations decay self-similarly at an algebraic rate which can be obtained by dimensional arguments; (ii) the ratio of anisotropic to isotropic fluctuations of a given intensity falls off in time as a power law, with an exponent approximately independent of the strength of the fluctuation; (iii) the decay of anisotropic fluctuations is not self-similar, their statistics becoming more and more intermittent as time elapses. We also investigate the early stages of the decay. The different short-time behavior observed in two experiments differing by the phase organization of their initial conditions gives a new hunch on the degree of universality of small-scale turbulence statistics, i.e. its independence of the conditions at large scales.Comment: 9 pages, 17 figure

Aerodynamic and Aeroacoustic Numerical Investigation of Turbofan Engines using Lattice Boltzmann Methods

International audienceIn recent years, lattice Boltzmann methods showed promising advantages over standard Navier-Stokes equation-based solvers. In this work, the capacity to predict both self noise and interaction noise is evaluated. First, a rod-airfoil interaction case is investigated, where the turbulence wake of the rod impinges the leading edge of the airfoil. Thereafter, a semi-infinite ducted axial fan is studied, where the turbulent boundary layers on each blades generate self noise which propagates into the duct, and radiates to the far-field. Subsequently, a ducted grid simulation is performed to verify the properties of the grid-generated turbulence. Finally, the grid and the axial-fan are combined within the same configuration, which comprises both self-noise and interaction noise. For each configuration, the agreements with experiments are satisfactory, however, acoustic propagation issues have been encounters from the duct intake to the free field. Nevertheless, the implemented wall model at the solid boundaries seems to correctly predict the acoustic sources on the blades

Inhibition of SLPI ameliorates disease activity in experimental autoimmune encephalomyelitis

<p>Abstract</p> <p>Background</p> <p>The secretory leukocyte protease inhibitor (SLPI) exerts wide ranging effects on inflammatory pathways and is upregulated in EAE but the biological role of SLPI in EAE, an animal model of multiple sclerosis is unknown</p> <p>Methods</p> <p>To investigate the pathophysiological effects of SLPI within EAE, we induced SLPI-neutralizing antibodies in mice and rats to determine the clinical severity of the disease. In addition we studied the effects of SLPI on the anti-inflammatory cytokine TGF-β.</p> <p>Results</p> <p>The induction of SLPI neutralizing antibodies resulted in a milder disease course in mouse and rat EAE. SLPI neutralization was associated with increased serum levels of TGF-β and increased numbers of FoxP3+ CD4+ T cells in lymph nodes. <it>In vitro</it>, the addition of SLPI significantly decreased the number of functional FoxP3+ CD25^hiCD4+ regulatory T cells in cultures of naive human CD4+ T cells. Adding recombinant TGF-β to SLPI-treated human T cell cultures neutralized SLPI's inhibitory effect on regulatory T cell differentiation.</p> <p>Conclusion</p> <p>In EAE, SLPI exerts potent pro-inflammatory actions by modulation of T-cell activity and its neutralization may be beneficial for the disease.</p

Awareness of cognitive decline trajectories in asymptomatic individuals at risk for AD

Background: Lack of awareness of cognitive decline (ACD) is common in late-stage Alzheimer’s disease (AD). Recent studies showed that ACD can also be reduced in the early stages. Methods: We described different trends of evolution of ACD over 3 years in a cohort of memory-complainers and their association to amyloid burden and brain metabolism. We studied the impact of ACD at baseline on cognitive scores’ evolution and the association between longitudinal changes in ACD and in cognitive score. Results: 76.8% of subjects constantly had an accurate ACD (reference class). 18.95% showed a steadily heightened ACD and were comparable to those with accurate ACD in terms of demographic characteristics and AD biomarkers. 4.25% constantly showed low ACD, had significantly higher amyloid burden than the reference class, and were mostly men. We found no overall effect of baseline ACD on cognitive scores’ evolution and no association between longitudinal changes in ACD and in cognitive scores. Conclusions: ACD begins to decrease during the preclinical phase in a group of individuals, who are of great interest and need to be further characterized. Trial registration: The present study was conducted as part of the INSIGHT-PreAD study. The identification number of INSIGHT-PreAD study (ID-RCB) is 2012-A01731-42