Impact on peel strength, tensile strength and shear viscosity of the addition of functionalized low density polyethylene to a thermoplastic polyurethane sheet calendered on a polyester fabric

International audienc

Peel strength impact of functionalized polyethylene to thermoplastic polyurethane calendered on a polyester fabric

International audienceMany producers use the extrusion calendering process for thermoplastic polyurethane coated fabrics. However, a technological lock is the ability to get a good adhesion of the coating with the fabric. Producers could increase the coating extrusion temperatures but TPU have a narrow extrusion temperatures range making it difficult to extrude. One solution is to make a blend with another polymer which has a higher extrusion temperature range. In the present work, the studies of the addition of LDPE and LLDPE-g-Ma in polyurethane coating on the tensile strength of the sheet and on the peel strength with a polyester fabric have been studied as well as the influence of the extrusion temperature. SEM observations and viscosity measurements have been performed to understand the behaviour of the different blends. Results show that extrusion temperature and penetration depth of the coating in the fabric have an influence on the peel strength

Peel strength impact of functionalized polyethylene to thermoplastic polyurethane calendered on a polyester fabric

International audienceMany producers use the extrusion calendering process for thermoplastic polyurethane coated fabrics. However, a technological lock is the ability to get a good adhesion of the coating with the fabric. Producers could increase the coating extrusion temperatures but TPU have a narrow extrusion temperatures range making it difficult to extrude. One solution is to make a blend with another polymer which has a higher extrusion temperature range. In the present work, the studies of the addition of LDPE and LLDPE-g-Ma in polyurethane coating on the tensile strength of the sheet and on the peel strength with a polyester fabric have been studied as well as the influence of the extrusion temperature. SEM observations and viscosity measurements have been performed to understand the behaviour of the different blends. Results show that extrusion temperature and penetration depth of the coating in the fabric have an influence on the peel strength

Microplastic and microfiber fluxes in the Seine River: Flood events versus dry periods

International audienc

Rev Epidemiol Sante Publique

Contexte et objectif : Lors d'un accident vasculaire cérébral ischémique dû à une occlusion d'un gros vaisseau, plus la thrombectomie mécanique (TM) est réalisée rapidement, meilleur est le pronostic fonctionnel. Cependant, l'organisation des soins ne permet pas systématiquement un accès rapide à la TM. L'objectif de notre étude était de déterminer les facteurs cliniques et organisationnels associés au délai d'accès à la TM. Méthodes : Nous avons réalisé une étude de cohorte dans le département de la Gironde, en France. Les patients nécessitant une TM et régulés par les Services d'Aide Médicale Urgente (SAMU) de Gironde entre le 01/01/2017 et le 31/12/2018 ont été inclus. Le délai d'accès à la TM correspondait à la différence entre le premier appel au SAMU et la ponction de l'aine pour TM. Les principales variables explicatives étaient : le type de parcours de soins (mothership (MS), drip and ship (DS) avec imagerie cérébrale réalisée au centre hospitalier de proximité (CHP) et DS sans imagerie au CHP) ; le score NIHSS ; la distance kilométrique pour accéder à la TM ; le moment de survenue de l'AVC (week-end ou jour férié, vacances scolaires, autre) ; l'âge et le sexe. Des modèles de régression linéaire ont été utilisés pour expliquer le délai d'accès à la TM. Les données manquantes ont été gérées à l'aide d'une procédure d'imputation multiple (spécification conditionnelle complète, Mice R-Package) exécutée dans notre modèle de régression linéaire multivariable. Une analyse quantitative du biais a été réalisée en pondérant le délai imputé d'accès à la TM et en identifiant le poids qui modifie les conclusions de notre analyse. Résultats : Parmi les 314 patients inclus, 152 étaient des femmes (48,4 %), et le score NIHSS moyen à l'admission était de 16,4. Deux cent deux (64,3 %) patients ont été pris en charge dans parcours MS. Le délai moyen entre le premier appel au SAMU et la ponction fémorale pour TM était de 251 minutes. Dans l'analyse multivariable, le délai d'accès à la TM était plus long lorsque les patients étaient pris en charge dans le parcours DS avec imagerie dans le CHP (+106 min, p=0,03), et encore plus long dans le parcourd DS sans imagerie dans le CHP (+197 min, p=0,002), par rapport au parcours MS. Le délai d'accès à la TM diminuait avec l'augmentation du score NIHSS (-6 min par point NIHSS, p<.0001). Dans notre analyse quantitative des biais, nous avons multiplié le délai imputé d'accès à la TM dans les parcours DS uniquement (avec ou sans imagerie dans le CHP) par des poids variant de 0,9 à 0,2 (délais imputés réduits de 10 % à 80 %). Avec une réduction de 40 % ou plus, il n'y avait plus de différence de délai d'accès à la TM entre les trois parcours de soins étudiés. Conclusions : Le parcours DS peut encore être raccourci en généralisant l'accès à l'imagerie cérébrale au sein des CHP. L'optimisation de l'orientation pré-admission vers la TM est un point majeur dans la prise en charge des accidents vasculaires cérébraux ischémiques dûs à une occlusion d'un gros vaisseau.BACKGROUND AND PURPOSE: When an ischaemic stroke due to a large vessel occlusion occurs, the sooner Mechanical Thrombectomy (MT) is performed, the better the functional prognosis. However, the organisation of care does not systematically allow rapid access to MT. The aim of our study was to determine the clinical and organisational factors associated with the time to access to MT. METHODS: We conducted a cohort study in Gironde County, France. Patients admitted for MT and regulated by the Gironde Emergency Medical Services (EMS) between 01/01/2017 and 31/12/2018 were included. The time to access to MT was the difference between the first call to EMS and groin puncture for MT. The main explanatory variables were: type of pathway (mothership (MS), drip and ship (DS) with cerebral imaging performed in the local hospital centre (LHC), and DS without imaging in the LHC); NIHSS score; driving distance to MT; time of stroke onset (weekend or holiday, school holidays, other); age and sex. Linear regression models were used to explain time to access to MT. Missing data were handled using a multiple imputation procedure (Full conditional specification, Mice R-Package) carried out in our multivariable linear regression model. A quantitative bias analysis was performed by weighing the imputed time to access to MT and identifying the weight changing the conclusions of our analysis. RESULTS: Among the 314 included patients, 152 were women (48.4%), and the mean NIHSS score was 16.4. Two hundred and two (64.3%) patients were managed through the MS pathway. The average time from onset to femoral puncture was 251 minutes. In the multivariate analysis, the time to MT was longer when patients were managed DS with imaging in the LHC pathway (+106 min, p = 0.03), and even longer in the DS without imaging in the LHC pathway (+197 min, p = 0.002), compared with MS. Time from onset to MT decreased with increasing NIHSS score (-6 min per NIHSS point, p <.0001). In our quantitative bias analysis, we multiplied the imputed time in access to MT in the DS pathways only (with or without imaging in the LHC) by weights varying from 0.9 to 0.2 (imputed delays reduced from 10% to 80%). With reduction of 40% or more, there was no longer any difference in time to access to MT between the three studied pathways. CONCLUSIONS: The DS pathway can be shortened by generalizing access to cerebral imaging in LHCs. Optimizing pre-admission orientation toward MT is a major issue in LVOS management

Development of flame-retarded PLA compositions by 3D printing of core-skin structures

International audienceThis work focused on the development of flame-retarded PLA compositions for additive manufacturing. Fused Filament Fabrication (FFF) was chosen as a technique to produce plate samples. Injected samples were also manufactured for comparison purpose. The nature of the flame retardants (FR), their contents and their distribution in the samples were varied. The microstructure was assessed in order to be related to fire performance of flame-retarded PLA structures. Fire behaviour was investigated via cone calorimeter tests. The results showed a significant decrease of the time to ignition (TTI) of 3D printed compared to injected samples, due to their higher porosity. However, for a given total FR content, concentrating FR close to the radiated surface proved to be a promising solution in order to optimise fire performance while preserving the mechanical properties of neat PLA

Controlling the distribution of fire retardants in poly(lactic acid) by fused filament fabrication in order to improve its fire behaviour

International audienceThis study focused on the development of skin/core structures with flame-retarded poly (lactic acid) (PLA) compositions, by additive manufacturing. For this purpose, the technique of Fused Filament Fabrication (FFF) was chosen. Plate samples were also manufactured by injection moulding for comparison purpose. The nature of the flame retardants (FR), their contents and their distribution in the samples were varied. The fire behaviour was investigated by cone calorimeter tests. The microstructure was characterized and related to the fire performances of each flame-retarded PLA structure. The results showed a significant decrease of the time to ignition (TTI) of 3D printed samples compared to the injected ones, due to their higher porosity. However, for a given total FR content, concentrating FR close to the radiated surface proved to be a promising solution in order to optimize fire performance while preserving the mechanical properties of neat PLA

Development of flame-retarded PLA compositions by 3D printing of core-skin structures

International audienc