Portail des publications scientifiques IMT Mines Alès
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Night-Time Apomorphine Infusion: Who Are the Best Candidates?
No full textInternational audienceBackground: We recently demonstrated in a randomized controlled trial (APOMORPHEE, NCT02940912) that night-time only subcutaneous apomorphine infusion improves sleep disturbances and insomnia in patients with advanced Parkinson's disease and moderate to severe insomnia. Objectives: To identify the best candidates for receiving night-time only subcutaneous apomorphine infusion in routine care. Methods: In this post-hoc analysis of APOMORPHEE, we compared the characteristics of patients according to whether they chose to continue night-time only subcutaneous apomorphine infusion at the end of the study period or not. Results: Half of the patients (22/42) chose to continue the treatment. Off duration (day or night), painful Off dystonia, and insomnia severity at baseline were associated with night-time only apomorphine continuation. Multivariate analysis retained only Off duration as an independent predictor of continuation. Conclusions:The best candidates for night-time only apomorphine are patients with severe and prolonged Off periods (day or night) and severe insomnia
Radiation induced graft polymerization of fluorinated monomers onto flax fabrics for the control of hydrophobic and oleophobic properties
No full textInternational audienceFunctional textiles have been one of the most studied topics in recent decades. Due to toxicity concerns, thetreatment of fabrics for non-wettable properties with fluorinated molecules is nowadays limited to short fluoroalkylchains. In this work, several fluorinated (meth)acrylic monomers such as 1,1,1,3,3,3-hexafluoroisopropylmethacrylate, 2-(perfluorobutyl)ethyl methacrylate, 1H,1H,2H,2H-perfluorooctyl methacrylate, 1H,1H,2H,2Hperfluorooctylacrylate and 1H,1H,2H,2H-perfluorodecyl methacrylate (denoted as M2, M4, M6, AC6 and M8,respectively) were grafted onto flax fabrics to improve their hydrophobic and oleophobic properties by radiograftingusing a pre-irradiation procedure. The effects of the length of the fluoroalkyl group of the monomer, theirradiation dose and the reaction time on the grafting rate were studied. The functionalization of flax fabrics bythese five monomers was confirmed by FTIR spectroscopy analysis. The morphology of the fibers before and aftertreatment was studied by scanning electron microscopy (SEM). The location of fluorine element in the flaxelementary fibers was assessed by SEM-EDX. The hydro- and oleophobic properties were determined by contactangle measurement using water and diiodomethane as solvents, respectively. The sliding angle was alsomeasured to assess the water repellency of hydrophobic fabrics. Significant fluorine contents were obtained forflax fibers irradiated and treated with 10 wt% solutions of monomer. Hydro- and oleophobic fabrics were obtainedfor flax irradiated even at a low dose of 5 kGy and treated with M4, with water and diiodomethane contactangles (CAs) of about 139◦ and 120◦, respectively. Superhydrophobic fabrics (CA = 150◦) were also achieved forsamples irradiated at 20, 50 and 100 kGy and treated with 10 wt% of M8. For this monomer, SEM analysisshowed the formation of spherical microparticles of fluoropolymer covering the surface of elementary fibers. Theformation of these particles is assumed to result from a dispersion polymerization mechanism. This is due to thefewer affinity of M8 with methanol and to the incompatibility of the formed polymer chains with this solventused for the grafting reaction
Monitoring of chemical and radiation grafting of vinyl phosphonic acid on natural fibers
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Functionalization of thiosemicarbazide/gellan gum for the enhancement of cadmium removal from aqueous solutions – Grafting of tributyl phosphate derivative
No full textInternational audienceTwo sorbents are successfully synthesized based on the chemical modification of gellan gum (GG). First, thiosemicarbazide is grafted onto GG to produce GEG-C. In a second step, GEG-C is functionalized with a derivative of tributyl phosphate (dTBP, giving GEG-P sorbent). The sorption properties are compared for recovery of Cd(II) from aqueous solutions. GEG-C is expected to bind Cd(II) through carboxylic, amine, and thiocarbonyl groups, while phosphate groups in GEG-P contribute to increase metal sorption. The chemical modification improves not only the uptake kinetics (equilibrium time ≈30 min, vs. 45 min) but also the sorption capacities (≈2.79 vs. 1.60 mmol Cd g−1), at optimum pH (i.e., pH 5). The functionalization also improves (a) the sorbent stability (weaker reduction of the loss in sorption efficiency after five cycles of reuse compared with GEG-C) and (b) the sorption selectivity in the presence of competitor ions (from equimolar multicomponent solutions), especially at pH 4. Different sorption mechanisms may be involved depending on the pH (deprotonation of reactive groups) including chelation (onto deprotonated amine and phosphonate groups) and ion exchange (protonated groups with metal cations). Cadmium sorption is reversed by contact with 0.3 M HCl solution. The functionalization (GEG-P) strongly increases the selectivity coefficient for Cd(II) against major elements in mining effluent, especially at pH higher than 5. These results confirm the interest of multifunctionality in the development of new sorbents based on renewable resources (such as gellan gum)
Foaming of PLA biocomposites by supercritical CO2 assisted extrusion process
No full textInternational audienceIn many industrial fields, the development of porous and lightweight polymer composite structures is of great interest. These structures may have several advantages compared to a massive solid of similar chemical nature, such as better mechanical properties, cushioning, insulation or sound and heat absorption. Three different methods are developed for the foaming of materials: batch, injection and extrusion foaming. These techniques employ highly toxic and harmful substances such as azodicarbonamide as blowing agents, which has increased the use of supercritical fluids as blowing agents, sc-CO2 being the most employed. In addition, petroleum-based thermoplastics are widely used as polymer matrices, but, due to the shortage of fossil resources and the rise of environmental concerns, biopolymers (bio-based and/or bio-degradable, polymers) are more and more used. In this context, the foaming of biopolymers using supercritical CO2 as a blowing agent has become a subject of interest. For this work, polylactic acid (PLA) is employed as the polymer matrix. PLA’s interesting properties have made it the most studied biopolymer, and consequently generated a great amount of interest in different industrial fields. The foaming of PLA biocomposites has been investigated before [1-2], but the effect of fillers on the cellular morphology remains a misunderstood and poorly studied subject.This work aims to explain the effects of size and aspect ratio of a filler as well as its content on the characteristics of PLA foams obtained by supercritical CO2-assisted extrusion process. Short (S) and long (L) cellulose fibres with aspect ratios (lenght/diameter) of 1.5 and 5-7 respectively, have been used as fillers. Fibres were compounded with the polymer through hot melt extrusion at different volume fractions (4 and 12 vol.%) (mass fractions 5 and 15 wt.% respectively). During the extrusion foaming process, two different volumetric flow rates of CO2 were studied (2.5 and 3 mL min-1), and the effect of die temperature was evaluated as well. Techniques as gas pycnometry, scanning electron microscopy (SEM) and modulated differential scanning calorimetry (MDSC) have been used to identify the characteristics of the produced foams
Cyber Security in Healthcare : Utilizing Artificial Intelligence and Database Technology to Enhance Understanding of Cyberattacks
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Development and Implementation of Automated Qualification Processes for the Identification of Pollutants in an Aquatic Environment from High-Resolution Mass Spectrometric Nontarget Screening Data
No full textInternational audienceEnvironmental pollution monitoring represents a major challenge due to the growing presence of a large and diverse number of potential contaminants. In complement to target analysis, nontarget analysis, via liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS), is increasingly used to provide a more comprehensive characterization of pollution. The challenge associated with this type of analysis is particularly related to the data treatment for substance identification. One of the main limitations is that all data must be manually reviewed, which is tedious and time-consuming. Machine learning algorithms aim to reproduce human behavior, and their capabilities were therefore evaluated to automatically identify substances in suspect screening approaches. After selecting the relevant features produced from LC/HRMS, seven different machine learning models were evaluated for each of the three different databases, which resulted in the selection of logistic regression (LR) and random forest (RF)-based algorithms. An interface was built to rank the identified substances and to assess the performance of the developed models. The LR model provided the best results when retention times were available. The developed LR and RF models were determined complementarily, particularly when no retention times were available. However, limitations were noticed when using a database containing different HRMS technologies
Brown Algal Residue for the Recovery of Metal Ions—Application to La(III), Cd(II), and Ni(II) Sorption
No full textInternational audienceRemoving hazardous metals and recovering valuable strategic metals from wastewater has become an important challenge for the industry. Herein, brown algal biomass residue (AR, after bio-stimulant extraction, currently poorly valorized) is tested for the removal of Ni(II), Cd(II), and La(III) from aqueous solutions. This valorization of industrial waste makes profit of residual amounts of alginate-based materials, which have a strong affinity for metal cations. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) techniques are used for characterizing metal/biosorbent interactions. Uptake kinetics are relatively fast (equilibrium being reached in 180–240 min). The Sips equation fits the sorption isotherms; the maximum sorption capacities at pH ≈5 reach up to 0.84 mmol La g−1, 0.92 mmol Cd g−1, and 0.78 mmol Ni g−1. In binary solutions, AR shows marked preference for La(III) over divalent cations. This selectivity may be increased by complexing base metals with EDTA, opening the route for the selective recovery of rare earth elements. HCl solution reveals more efficient (>90% for La(III), ≈82% for Cd(II) and Ni(II)) than CaCl2 solution at pH 2 for metal desorption. This waste residue from biostimulant extraction (in brown algal biomass) can be valorized for the recovery of hazardous and strategic metal ions