Publications by authors named "Boissier C"

Walking rehabilitation is the cornerstone of patients with peripheral arterial disease (PAD) treatment. In order to propose a personalised walking rehabilitation program to each patient, it is important to know the PAD-patients walking characteristics. Such data are lacking in the literature.

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Introduction: Objective Structured Clinical Examinations (OSCEs) assess professional performance in a simulated environment. Following their integration into the reform of the 2nd cycle of medical studies (R2C), this pedagogical modality was implemented in France. This study investigates the variability of students' OSCE scores, as well as their inter-rater reproducibility.

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Powders are usually dispensed, blended, and transferred between different manufacturing steps in so-called Intermediate Bulk Containers (IBCs), and discharge from an IBC plays a critical role in the ability to manufacture high-quality tablets. To better understand IBC discharge, the flow behavior of selected excipients was comprehensively characterized using a number of techniques including the Hausner ratio/Carr's index, Erweka flow test, FlowPro flow test, shear test and wall friction test as well as FT4 powder rheometer experiments. Jenike's hopper design methodology was then used to predict the minimum non-arching outlet diameter and the mode of flow.

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Background: Characterisation of arterial Doppler waveforms is a persistent problem and a source of confusion in clinical practice. Classifications have been proposed to address the problem but their efficacy in clinical practice is unknown. The aim of the present study was to compare the efficacy of the categorisation rate of Descotes and Cathignol, Spronk et al.

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A multivariate TOF-SIMS methodology has been developed and applied to quantify surface composition and chemical distribution for dry powder blends. Surface properties are often critical to the behavior of powder formulations, especially in the case of dry powders for inhalation, as surface properties directly affect inter-particulate forces and, hence, the dispersibility of the formulation. The mass spectrum at each pixel was fit to a linear combination of reference spectra obtained by non-negatively constrained alternating least squares.

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Peripheral arterial disease is a result of atheroma. This disease is frequent in subjects with vascular risk factors. This disease is also frequent in low income countries.

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The objective of this study was to characterize the rheology of a pharmaceutical material in the context of the µ(I)-rheology model and to use this model to predict powder flow in a manufacturing operation that is relevant to pharmaceutical manufacturing. The rheology of microcrystalline cellulose spheres was therefore characterized in terms of the μ(I)-rheology model using a modified Malvern Kinexus rheometer. As an example of an important problem in pharmaceutical manufacturing, the flow of these particles from a hopper was studied experimentally and numerically using a continuum Navier-Stokes solver based on the Volume-Of-Fluid (VOF) interface-capturing numerical method.

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Polymer films based on mixtures of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) have been widely used to coat pellets and tablets to modify the release profile of drugs. For three different EC/HPC films we used H and F MRI in combination with a designed release cell to monitor the drug, polymer and water in 5 dimensional (5D) datasets; three spatial, one diffusion or relaxation and a temporal dimension, in real time. We observed that the water inflow through the films correlated with the initiation of the dissolution of the drug in the tablet beneath the film.

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Mannitol and lactose are commonly used fillers in pharmaceutical tablets, available in several commercial grades that are produced using different manufacturing processes. These grades significantly differ in particulate and powder properties that impact tablet manufacturability. Choice of sub-optimum type or grade of excipient in tablet formulation can lead to manufacturing problems and difficulties, which are magnified during a continuous manufacturing process.

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Lower extremity peripheral artery disease is a frequent disease. Arterial Doppler waveforms analysis is a key element in vascular medicine, especially to diagnose lower peripheral artery disease. Although Doppler waveforms are often used, descriptions are highly heterogeneous.

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Background: According to the World Health Organization, individuals should walk 10,000 per day. Our aim was to determine the factors influencing this objective by using connected activity trackers.

Methods: Anonymized data of 10,000 regular users of the Withings pulse O over a 3-month period.

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Appropriate selection of excipient grade during tablet formulation development depends on thorough knowledge in their compaction and flow properties. Each chemically unique pharmaceutical excipient is usually available in several commercial grades that are widely different in powder properties, which influence their performance for a specific formulation application. In this work, 11 grades of mannitol were systematically characterized, in terms of their particulate, flow and tableting properties, and compared against 5 grades of lactose.

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Peripheral artery disease of the lower limbs (PAD) is a common disease. Evaluation of PAD is primarily based on non-invasive examinations with analysis of the arterial Doppler signal being a key element. However, the description of arterial Doppler waveforms morphologies varies considerably across medical schools and from country to country.

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The structure of a material, in particular the extremes of crystalline and amorphous forms, significantly impacts material performance in numerous sectors such as semiconductors, energy storage, and pharmaceutical products, which are investigated in this paper. To characterize the spatial distribution for crystalline-amorphous forms at the uppermost molecular surface layer, we performed time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) measurements for quench-cooled amorphous and recrystallized samples of the drugs indomethacin, felodipine, and acetaminophen. Polarized light microscopy was used to localize crystallinity induced in the samples under controlled conditions.

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Understanding how the pore structure influences the mass transport through a porous material is important in several applications, not the least in the design of polymer film coatings intended to control drug release. In this study, a polymer film made of ethyl cellulose and hydroxypropyl cellulose was investigated. The 3D structure of the films was first experimentally characterized using confocal laser scanning microscopy data and then mathematically reconstructed for the whole film thickness.

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Drug release from oral pharmaceutical formulations can be modified by applying a polymeric coating film with controlled mass transport properties. Interaction of the coating film with water may crucially influence its composition and permeability to both water and drug. Understanding this interaction between film microstructure, wetting, and mass transport is important for the development of new coatings.

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Background: The use of new oral anticoagulants (NOACs) in patients with impaired renal function has raised major concerns, in particular the possibility of an increased risk of bleeding due to accumulation. The aims of this work were to assess the safety of NOACs in patients with renal failure and describe the relationship between clinical events and drug renal excretion magnitude.

Methods: All phase III trials comparing NOACs with vitamin K antagonists (VKAs) in patients with estimated glomerular filtration (eGFR) rate < 50 mL min(-1) were eligible.

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The stiffness of the arterial wall, which is modified by many cardiovascular diseases such as atherosclerosis, is known to be an indicator of vulnerability. This work focuses on the in vivo quantification of the stiffness of the common carotid artery (CCA) by applying the Magnitude Based Finite Element Model Updating (MB-FEMU) method to 13 healthy and diseased volunteers aged from 24 to 76 years old. The MB-FEMU method is based on the minimisation of the deviation between the image of a deformed artery and a registered image of this artery deformed by means of a finite elements analysis.

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Quantifying the stiffness properties of soft tissues is essential for the diagnosis of many cardiovascular diseases such as atherosclerosis. In these pathologies it is widely agreed that the arterial wall stiffness is an indicator of vulnerability. The present paper focuses on the carotid artery and proposes a new inversion methodology for deriving the stiffness properties of the wall from cine-MRI (magnetic resonance imaging) data.

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Background: Sleep-disordered breathing (SDB) has emerged as an independent risk factor for carotid atherosclerosis (CA) and cerebrovascular disease in middle-aged subjects. Currently, there is no study providing a causal relationship between SDB and cerebrovascular lesions in elderly.

Objective: To assess the impact of SDB on CA in a cohort of healthy elderly subjects.

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The major aim of this work was to study the effect of two process parameters, temperature and coating flow, on permeability to water and structure of free films sprayed from mixtures of ethyl cellulose (EC), hydroxypropyl cellulose (HPC), and ethanol. The films were sprayed in a new spraying setup that was developed to mimic the film coating process in a fluid bed and to provide well controlled conditions. EC and HPC phase separated during the film drying process, and EC- and HPC-rich domains were formed.

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