The Chikungunya Epidemic on La Réunion Island in 2005–2006: A Cost-of-Illness Study

For a long time, studies of chikungunya virus infection have been neglected, but since its resurgence in the south-western Indian Ocean and on La Réunion Island, this disease has been paid greater amounts of attention. The economic and social impacts of chikungunya epidemics are poorly documented, including in developed countries. This study estimated the cost-of-illness associated with the 2005–2006 chikungunya epidemics on La Réunion Island, a French overseas department with an economy and health care system of a developed country. “Cost-of-illness” studies measure the amount that would have been saved in the absence of a disease. We found that the epidemic incurred substantial medical expenses estimated at €43.9 million, of which 60% were attributable to direct medical costs related, in particular, to expenditure on medical consultations (47%), hospitalization (32%) and drugs (19%). The costs related to care in ambulatory and hospitalized cases were €90 and €2000 per case, respectively. This study provides the basic inputs for conducting cost-effectiveness and cost-benefit evaluations of chikungunya prevention strategies

Damage of woven composite under tensile and shear stress using infrared thermography and micrographic cuts

Infrared thermography was used to study damage developing in woven fabrics. Two different experiments were performed, a ±45° tensile test and a rail shear test. These two different types of tests show different damage scenarios, even if the shear stress/strain curves are similar. The ±45° tension test shows matrix hardening and matrix cracking whereas the rail shear test shows only matrix hardening. The infrared thermography was used to perform an energy balance, which enabled the visualization of the portion of dissipated energy caused by matrix cracking. The results showed that when the resin is subjected to pure shear, a larger amount of energy is stored by the material, whereas when the resin is subjected to hydrostatic pressure, the main part of mechanical energy is dissipated as heat

Chikungunya Virus Neutralization Antigens and Direct Cell-to-Cell Transmission Are Revealed by Human Antibody-Escape Mutants

Chikungunya virus (CHIKV) is an alphavirus responsible for numerous epidemics throughout Africa and Asia, causing infectious arthritis and reportedly linked with fatal infections in newborns and elderly. Previous studies in animal models indicate that humoral immunity can protect against CHIKV infection, but despite the potential efficacy of B-cell-driven intervention strategies, there are no virus-specific vaccines or therapies currently available. In addition, CHIKV has been reported to elicit long-lasting virus-specific IgM in humans, and to establish long-term persistence in non-human primates, suggesting that the virus might evade immune defenses to establish chronic infections in man. However, the mechanisms of immune evasion potentially employed by CHIKV remain uncharacterized. We previously described two human monoclonal antibodies that potently neutralize CHIKV infection. In the current report, we have characterized CHIKV mutants that escape antibody-dependent neutralization to identify the CHIKV E2 domain B and fusion loop “groove” as the primary determinants of CHIKV interaction with these antibodies. Furthermore, for the first time, we have also demonstrated direct CHIKV cell-to-cell transmission, as a mechanism that involves the E2 domain A and that is associated with viral resistance to antibody-dependent neutralization. Identification of CHIKV sub-domains that are associated with human protective immunity, will pave the way for the development of CHIKV-specific sub-domain vaccination strategies. Moreover, the clear demonstration of CHIKV cell-to-cell transmission and its possible role in the establishment of CHIKV persistence, will also inform the development of future anti-viral interventions. These data shed new light on CHIKV-host interactions that will help to combat human CHIKV infection and inform future studies of CHIKV pathogenesis

Thermomechanical Coupling & Dynamic Crack Propagation

International audienceThermomechanical coupling is studied in dynamic fracture mechanisms. The crack propagation problem is formalized within the framework of the thermodynamics of irreversible processes to determine their essential parameters and couplings. The analytical approach developed herein is based on the linear elastic mechanics of fracture, including the inertial effects and thermomechanical couplings. For a one-dimensional restriction, the mechanics and thermics equations are uncoupled in the entire structure, with simplified thermomechanical coupling at the crack-tip. This study aims to determine the criteria for fracture initiation and propagation in the presence of heating and inertial effects

Silver linked polyoxometalate open frameworks (Ag-POMOFs) for the directed fabrication of silver nanomaterials

A design approach for the preparation of the {(DMAH)<sub>7</sub>[H<sub>2</sub>SbW<sub>18</sub>O<sub>60</sub>]} (<b>DMAH-2</b>) and {(DMAH)<sub>7</sub>[H<sub>2</sub>BiW<sub>18</sub>O<sub>60</sub>]} (<b>DMAH-3</b>) (DMAH = dimethylammonium) systems in a highly pure crystalline form is presented, and the latter is characterized by electrospray ionization mass spectrometry (ESI-MS) methods for the first time. These, together with the archetypal [W<sub>10</sub>O<sub>32</sub>] cluster, are used as precursors for the formation of unique framework materials incorporating Ag(I) as a linking species. The systems are fully characterized by X-ray crystallography, elemental analysis, IR and thermogravimetric analysis (TGA), and the pyrolysis of the {Ag<sub>4</sub>-W<sub>10</sub>O<sub>32</sub>} system (<b>1</b>) leads to the formation of silver microparticles embedded in the resulting tungsten oxide and this has been observed by us previously with other systems. In contrast, the carefully controlled decomposition of the antimony and bismuth systems {Ag<sub>418</sub>O<sub>60</sub>} (<b>Ag-2</b>) and {Ag<sub>4</sub>-SbW<sub>18</sub>O<sub>60</sub>} (<b>Ag-3</b>) gives rise to the formation of highly pure, discrete silver microparticles as confirmed by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. These unique materials may be interesting for applications such as catalysis, antimicrobial agents, or electroactive/photoactive coatings, and this work demonstrates how the molecular organization of the building blocks on the nanoscale can affect the assembly of materials over a range of length scales