Efficient and rapid multiscale approach of polymer membrane degradation and stability: Application to formulation of harmless non-oxidative biocide for polyamide and PES/PVP membranes

International audienceMembrane cleaning and disinfection is a bottleneck in the filtration processes of the food industry. Disinfection by oxidative agents, such as NaOCl, have been clearly identified as the main responsible of the accelerated ageing of polymer membranes. The development of new formulated biocide detergents allowing to respect the integrity of polymer membranes is our objective. A major difficulty to overcome is to have a method making it possible to rapidly demonstrate whether the membrane will age after a long-time contact with the biocide in industrial conditions of use. However, nowadays the estimation of membrane ageing is mainly achieved by long-time consuming methods, limiting biocide and detergent developments. This paper proposes an original approach allowing a time-efficient discrimination of biocide detergent prototypes with respect to the membrane long-term ageing. The methodology is firstly based on the use of microwaves activation to accelerate the membrane degradation (if any) in the biocide solution set at a concentration selected to avoid too severe degradations never reached at industrial scale. Secondly, the combination of MW results and short time filtration gives rapidly relevant information about the suitability (or not) of a tested prototype with respect to the membrane flux behaviour. ATR-FTIR characterisation is shown to be relevant as the single analytical tool to follow the entire approach. Finally, only the promising prototype enter in long-term filtration validation tests, with a real opportunity to avoid unnecessary experiments. For the sake of the demonstration, the methodology is applied aiming at the formulation of a non-oxidative formulated biocide detergent that can be used either for RO or UF. The results evidence a non-intuitive conclusion: the new biocide validated for RO polyamide membrane (fragile toward NaOCl biocide oxidant and hydrophilic) has to be avoided for the more chemically resistant but also more hydrophobic UF PES/PVP membrane

Immunization and multiple sclerosis: Recommendations from the French Multiple Sclerosis Society

International audienceObjectives: To establish recommendations on immunization for patients with multiple sclerosis (MS).Background: Vaccines have been suspected in the past to trigger MS and relapses. With the extension of the immunoactive treatment arsenal, other concerns have been raised more recently about an increased risk of infection or a decreased effectiveness of immunization in immunosuppressed patients.Methods: The French Group for Recommendations into Multiple Sclerosis (France4MS) performed a systematic search of papers in Medline and other university databases (January 1975-June 2018). The RAND/UCLA appropriateness method was chosen to review the scientific literature and to formalize the degree of agreement among experts on 5 clinical questions related to immunization and MS. Readers from the steering committee conducted a systematic analysis, wrote a critical synthesis and prepared a list of proposals that were evaluated by a rating group of 28 MS experts. The final version of the recommendations was finally reviewed by a reading group of 110 health care professionals and classified as appropriate, inappropriate or uncertain.Results: Neurologists should verify the vaccination status as soon as MS is diagnosed and before disease-modifying treatments (DMTs) are introduced. The French vaccination schedule applies to MS patients and seasonal influenza vaccination is recommended. In the case of treatment-induced immunosuppression, MS patients should be informed about the risk of infection and the vaccination standards of the French High Council of Health should be applied. Live attenuated vaccines are contra-indicated in patients recently treated with immunosuppressive drugs, including corticosteroids; other vaccines can be proposed whatever the treatment, but their effectiveness may be partly reduced with some drugs.Conclusion: Physicians and patients should be aware of the updated recommendations for immunizations of patients with MS