Impact of multiple sclerosis on employment and income: Insights from a random sample representative of private sector employees in France using longitudinal administrative data.

In France, few data sources are available to estimate the impact of multiple sclerosis (MS) on job retention and its consequences on the level of resources, especially in large representative samples. The aim of the present study was to measure impact of MS on employment rates, wages and income (including unemployment benefit, sickness benefit and disability pension) by comparing work trajectories of people living with MS with those of a matched control group. We used the HYGIE database, which is the result of the linkage of two administrative databases in the private sector for a random sample of over 900,000 people. In order to identify the causal effect of MS on employment after 1 to 20 years, the difference-in-differences method with matching (age, sex, career and health history) was used, overall and in subgroups. The year of entry in long-term disease status for MS was used to approximate the onset of MS. Overall, 946 people with MS were included. Their situation was fairly favorable before MS (88.1% in employment, resources higher than the median for the general population), but MS had strong and continuous negative effects. Indeed, at 10 years, the employment rate fell by 28.6 percentage points (pp) and the disability pension allowance increased by 50.5 pp; the wage percentile fell by 19.2 pp and the replacement income accounted for a growing share of total income (+ 39.7 pp). Although administrative data had several strengths, clinical information on the severity of the disease or on its therapeutic management was not available. In conclusion, this study shows that the effects of MS on the employed population in the private sector occur early in the disease course and are cumulative, and that replacement income helps to reduce the loss of resources thanks to the French health and social system.

Robust raspberry-like metallo-dielectric nanoclusters of critical sizes as SERS substrates.

Raspberry-like nano-objects made of large plasmonic satellites (>10 nm) covering a central dielectric particle have many potential applications as photonic materials, superlenses and (bio-) sensors, but their synthesis remains challenging. Herein, we show how to build stable and robust raspberry-like nano-systems with close-packed satellites, by combining monodisperse silica particles (80 or 100 nm diameter) and oppositely charged noble metal nanoparticles (Au or Ag) with well-defined sizes (10-50 nm). The spectral characteristics of their associated plasmonic resonances (wavelength, linewidth, extinction cross-section) and the electromagnetic coupling between satellites were observed using the spatial modulation spectroscopy technique and interpreted through a numerical model. The composite nano-objects exhibit numerous hot spots at satellite junctions, resulting in excellent surface-enhanced Raman scattering (SERS) performance. The SERS efficiency of the raspberry-like clusters is highly dependent on their structure.

Templated growth of gold satellites on dimpled silica cores.

We synthesize robust clusters of gold satellites positioned with tetrahedral symmetry on the surface of a patchy silica core by adsorption and growth of gold on the patches. First we conduct emulsion polymerization of styrene in the presence of 52 nm silica seeds whose surface has been modified with methacryloxymethyltriethoxysilane (MMS). We derive four-dimple particles from the resulting silica/polystyrene tetrapods. Polystyrene chains are covalently bound to the silica surface within the dimples due to the MMS grafts and they may be thiolated to induce adsorption of 12 nm gold particles. Using chloroauric acid, ascorbic acid and sodium citrate at room temperature, we grow gold from these 12 nm seeds without detachment from or deformation of the dimpled silica surface. We obtain gold satellites of tunable diameter up to 140 nm.

Synthesis of size-monodisperse spherical Ag@SiO2 nanoparticles and 3-D assembly assisted by microfluidics.

This article reports a one-step approach for the fabrication of highly uniform, spherical Ag particles with tailored dimensions ranging from 10 to 30 nm. Coated with silica shell, the high uniformity of the particles allows their spontaneous assembly into millimeter-long extended 3-D arrays with transverse dimensions of tens of micrometers, using a microfluidic evaporation-based process.

Silica encapsulated manganese perovskite nanoparticles for magnetically induced hyperthermia without the risk of overheating.

Nanoparticles of manganese perovskite of the composition La(0.75)Sr(0.25)MnO(3) uniformly coated with silica were prepared by encapsulation of the magnetic cores (mean crystallite size 24 nm) using tetraethoxysilane followed by fractionation. The resulting hybrid particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. Both calorimetric heating experiments and direct measurements of hysteresis loops in the alternating field revealed high specific power losses, further enhanced by the encapsulation procedure in the case of the coated particles. The corresponding results are discussed on the basis of complex characterization of the particles and especially detailed magnetic measurements. Moreover, the Curie temperature (335 K) of the selected magnetic cores resolves the risk of local overheating during hyperthermia treatment.

Sr-hexaferrite/maghemite composite nanoparticles-possible new mediators for magnetic hyperthermia.

Composite nanoparticles with variable ratios of M-type Sr-hexaferrite and maghemite phases were prepared via the sol-gel method employing polyvinylalcohol as the stabilizing agent, followed by thermal treatment at 600 °C for 32-190 min. The measurements in static magnetic field revealed considerable variation of the coercivity and remanence depending on the relative content of the highly magnetically anisotropic Sr-hexaferrite phase. Calorimetric heating experiments were carried out on aqueous gel suspensions under an alternating magnetic field of maximum amplitude H(max) = 15.1-68.4 kA m(-1) and frequency ν = 108 kHz. They showed a strong dependence of the heating efficiency on the coercivity and remanence of the composites, with a specific absorption rate (SAR) value ranging from units to tens of W/g(Fe(ferrimagnetic)).

Acrylate intercalation and in situ polymerization in iron-, cobalt-, or manganese-substituted nickel hydroxides.

A chimie douce route based on successive redox and exchange reactions has allowed us to prepare new hybrid organic-inorganic materials, composed of polyacrylate macromolecules intercalated into layered double hydroxides (LDHs), deriving from Ni(OH)(2). Monomer intercalation and in situ polymerization mechanisms have appeared to be strongly dependent upon the nature of the substituting cation in the slabs. In the case of iron-based LDHs, a phase containing acrylate monomeric intercalates has been isolated and identified by X-ray diffraction and infrared spectroscopy. Second, interslab free-radical polymerization of acrylate anions has been successfully initiated using potassium persulfate. In cobalt- or manganese-based LDHs, one-step polymerization has been observed, leading directly to a material containing polyacrylate intercalate.

PMMA-based composite materials with reactive ceramic fillers: IV. Radiopacifying particles embedded in PMMA beads for acrylic bone cements.

New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS) and embedded in poly(methylmethacrylate-co-ethylacrylate) beads with about 7 mol% of ethyl acrylate repeating units. The encapsulation was performed through a conventional suspension polymerization process. The influence of (i) the concentration of the dispersion stabilizer and (ii) the alumina content upon the shape, size, and size distribution of the acrylic beads was studied. Cements were prepared from each batch by hand-mixing alumina-filled acrylic beads with a liquid monomer mixture containing methyl methacrylate, n-butyl methacrylate, and N,N-dimethyl-p-toluidine. Benzoyl peroxide was previously added to the solid part. The powder-to-liquid ratio was equal to 2 for each formulation. Compressive strength of cured cement decreases with alumina content, whereas compressive modulus remains roughly constant. These results are in contradiction to those obtained for cements based on a mixture of gamma-MPS-treated alumina and unfilled acrylic beads. Nevertheless, they are interpreted in terms of alumina arrangement in the cement. In the first case, alumina particles contribute to the reinforcement of the dispersed acrylic phase, with poor benefits for the whole materials. In the second case, they allow the reinforcement of the continuous acrylic phase and, therefore, the cement's one.

PMMA-based composite materials with reactive ceramic fillers: part III: radiopacifying particle-reinforced bone cements.

New acrylic bone cements were prepared from alumina particles previously treated by 3-(trimethoxysilyl)propylmethacrylate (gamma-MPS), able to act both as radiopacifying and reinforcing agents. The present study deals with the handling characteristics and the compressive behavior of such cements. The influence of the particles morphology, their surface-modification by gamma-MPS bonding agent, their concentration in the cement, the powder-to-liquid ratio and the benzoyl peroxide concentration are reported. The role of grafted gamma-MPS molecules as coupling agent was confirmed. For several formulations, compressive strength and modulus reached 150 MPa and 3400 MPa respectively. Limitations in the use of such formulations are also comprehensively discussed.