Risk of myocardial infarction with use of selected nonsteroidal anti-inflammatory drugs in spondyloarthritis patients

BACKGROUND: Spondyloarthritis (SpA) is associated with increased risk of myocardial infarction (MI); the risk may be due to the underlying inflammatory disease, or also due to medications that increase MI risk, such as certain non-steroidal anti-inflammatory drugs (NSAIDs). OBJECTIVES: 1. To describe the risk of myocardial infarction (MI) among patients with spondyloarthritis who are prescribed NSAIDs 2. To compare the pattern of MI risk with specific NSAID use among spondyloarthritis patients with the pattern of risk among patients with osteoarthritis (OA) METHODS: Nested case-control studies were performed using 1994–2015 data from The Health Improvement Network (THIN). Underlying cohorts included adult patients with incident SpA or OA had >1 NSAID prescriptions and no history of MI. In each cohort, we matched cases of incident MI to four controls without MI. NSAID use was categorized as: (A) current (prescription end date 0–180 days prior to index date), (B) recent (181–365 days), or (C) remote (>365 days). We performed conditional logistic regression to compare the odds of current or recent NSAID use relative to remote use of any NSAID, considering diclofenac and naproxen specifically. RESULTS: Within the SpA cohort of 8140 and the OA cohort of 244,399, there were 115 and 6287 MI cases, respectively. After adjustment, among SpA subjects, current diclofenac use was associated with an OR of 3.05 (95% CI 1.48–6.29; Table 2) for MI. Naproxen use was not associated with any increase (adjusted OR 1.25, 95% CI 0.56–2.78). A ratio of ORs for SpA/diclofenac relative to OA/diclofenac was 2.35 (1.10–4.90).2019-06-12T00:00:00

Bi-directional top hat D-Scan: single beam accurate characterization of nonlinear waveguides

The characterization of a third order nonlinear integrated waveguide is reported for the first time by means of a top-hat Dispersive-Scan (D-Scan) technique, a temporal analog of the top-hat Z-Scan. With a single laser beam, and by carrying two counter-directional nonlinear transmissions to assess the input and output coupling efficiencies, a novel procedure is described leading to an accurate measurement of the TPA figure of merit, the effective Two-Photon Absorption (TPA) and optical Kerr (including the sign) coefficients. The technique is validated in a silicon strip waveguide for which the effective nonlinear coefficients are measured with an accuracy of $\pm 10~\%$Comment: 5 pages, 4 figure

A coupled parametric and nonparametric approach for modal analysis of a satellite

This study takes place in the context of dynamical prediction for satellite structures. Aims of such studies are to survey the dynamical response of satellite equipment and components, to check that requirements are correct and to give prediction of vibration levels, which are inputs for the experimental test validation according to the launcher specification. This prediction is done by modal analysis performed on a numerical model built by finite element method. Uncertainties on equipment and components properties lead to random frequency response function (FRF). This paper aims at understanding how modal approach can be adapted to probabilistic framework in order to calculate cumulative density function or, at least, some quantiles of a FRF. Starting point of deterministic modal analysis is the study of a single degree of freedom (DOF) system. C. Heinkelé analytically expresses the probability density function (PDF) of the FRF of an oscillator with a random natural pulsation following a uniform law. We have generalized this work to random natural pulsation following a law of finite variance. Then, the expression of a FRF between two DOF of the structure is a linear function of random oscillators FRF and DOF components of random eigenvectors. Assuming that random eigenvectors are close to their means, we have access to the characteristic function of the random FRF between two DOF as a multi-dimensional integral with respect to the joint PDF of the oscillators FRF. This paper mainly focuses on two major points which are calculation of oscillators joint PDF and inversion of characteristic functions. The first one is tackled by copulas theory. Dependence structure of random eigenvalues are identified and modeled by a copula. Then we apply results on copulas transformations to obtain joint PDF of oscillators FRF. Classical results concern monotonic transformations but we extended these ones to non-monotonic cases. Concerning inversion of characteristic function, several methods are studied to numerically compute the Gil-Pelaez formula. This approach allows to access some FRF quantiles by numerical integration which error can be controlled. Moreover, an interesting point is the flexibility in the identification of the random eigenvalues PDF. This is especially interesting in order to couple parametric identification with nonparametric one, when only few dispersion informations are given for equipments, housed in the satellite primary structure

Determination of Bootstrap confidence intervals on sensitivity indices obtained by polynomial chaos expansion

L’analyse de sensibilité a pour but d’évaluer l’influence de la variabilité d’un ou plusieurs paramètres d’entrée d’un modèle sur la variabilité d’une ou plusieurs réponses. Parmi toutes les méthodes d’approximations, le développement sur une base de chaos polynômial est une des plus efficace pour le calcul des indices de sensibilité, car ils sont obtenus analytiquement grâce aux coefficients de la décomposition (Sudret (2008)). Les indices sont donc approximés et il est difficile d’évaluer l’erreur due à cette approximation. Afin d’évaluer la confiance que l’on peut leur accorder nous proposons de construire des intervalles de confiance par ré-échantillonnage Bootstrap (Efron, Tibshirani (1993)) sur le plan d’expérience utilisé pour construire l’approximation par chaos polynômial. L’utilisation de ces intervalles de confiance permet de trouver un plan d’expérience optimal garantissant le calcul des indices de sensibilité avec une précision donnée

Télédétection et cartographie à petite échelle des paysages de la France de l’Ouest

Les images des satellites NOAAAVHRR sont utilisées dans le but d’établir une cartographie détaillée des paysages ruraux dans la France de l’Ouest. Douze images de 1985 à 1990 représentant l’indice de végétation NDVI ont été sélectionnées. Une analyse discriminante pas à pas permet de classer les pixels de l’image en fonction de 16 échantillons choisis comme représentatifs des types de paysages et des régions agricoles de l’Ouest. Les limites des classes ainsi obtenues sont fort comparables aux cartes communales thématiques d’utilisation du sol des atlas régionaux

On-line monitoring of the transesterification reaction carried out in microreactors using near infrared spectroscopy

Biodiesel can be produced from vegetable oils, animal fats, and waste cooking oils by transesterification with ethanol (also called ethanolysis) in order to substitute fossil fuels. In this work, the batch ethanolysis of high oleic sunflower oil was transferred into a continuous microstructured device, which induces a better control of heat and mass transfers. Various parameters were studied, notably the initial ethanol to oil molar ratio. An innovative method using NIR spectroscopy was also developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol in microreactors (circular PFA tube 1/1600 OD, 0.0200 ID). The reactions were monitored directly in the microreactors through sequential scans of the reaction medium by the means of an adequate probe. The asset of the method is that no sample collection or preparation is necessary. Partial Least Squares regression was used to develop calibration and prediction models between NIR spectral data and analytical data obtained by a reference method (gas chromatography with flame ionization detection, GC–FID). This method is fast, safe, reliable, nondestructive and inexpensive contrary to conventional procedures, such as gas chromatography and high performance liquid chromatography generally used to determine the composition of crude transesterification medium