Inter- and intramolecular Diels-Alder/retro-Diels-Alder reactions of 4-silylated oxazoles

4-Silylated oxazoles have been shown to undergo inter- and intramolecular Diels-Alder/retro-Diels-Alder reactions with electron-poor alkynes to generate polysubstituted furans. The ease of synthesis of the requisite oxazoles by the rhodium-catalysed condensation of nitriles with silylated diazoacetate greatly increases the scope of this reaction

Synthesis of highly substituted allenylsilanes by alkylidenation of silylketenes

BACKGROUND: Allenylsilanes are useful intermediates in organic synthesis. An attractive, convergent but little used approach for their synthesis is the alkylidenation of stable silylketenes. Reactions thus far have been limited to the use of unsubstituted silylketenes (or equivalents) with stabilised or semi-stabilised ylides only. The current study explores the reactions of substituted ketenes prepared through rhodium(II)-mediated rearrangement of silylated diazoketones. RESULTS: A range of novel 1,3-disubstituted and 1,3,3-trisubstituted allenylsilanes were prepared using stabilised and semi-stabilised ylides. Alkylidenation with non-stabilised phosphorus ylides was not viable, but the use of titanium-based methylenating reagents was successful, allowing access to 1-substituted allenylsilanes. CONCLUSION: Many novel allenylsilanes may be accessed by alkylidenation of substituted silylketenes. Importantly, for the first time, simple methylenation of silylketenes has been achieved using titanium carbenoid-based reagents

Anxieties in modern society related to food and advertising. An exploratory study of the Danonino brand in a cross-cultural perspective.

International audienceIndustrialisation of foods, the obesity pandemic and inadequate information available about food highlight the risks in modern food products. This explorative and qualitative paper creates a theoretical framework for understanding anxiety, food and advertising in the promotion of children's products and to explore how anxieties relating to children and food are dealt with in advertisements aimed at global markets. The analysis is based on a collection of 175 advertisements for the Danonino brand between 2001 and 2007 broadcast in six European countries. Results show that anxieties are at play in various ways in the "motherchild " relationship with regard to food, and that anxiety is enacted differently according to specific cultural backgrounds

Novel Thermoplastic Fibre-Metal Laminates Manufactured by Vacuum Resin Infusion: The Effect of Surface Treatments on Interfacial Bonding

The manufacturing process of a new generation of thermoplastic fibre-metal laminates (TP-FMLs) was investigated. A vacuum assisted resin infusion method was used to produce the hybrid laminates. The effect of various chemical and physical treatments on the surface morphology of the aluminium (Al) alloy sheets and on the bond strength at the metal-composite interface was examined. The wettability, topography and chemical composition of the treated Al alloy sheets were studied by employing contact-angle goniometry, coherence scanning interferometry, profilometry and X-ray photoelectron spectroscopy. The results showed that the applied treatments on the Al alloy sheet changed the surface morphology and surface energy in a different degree, which in turn effectively enhanced the interfacial bond strength between the constituents. In addition, the flexural, interlaminar shear strength and interlaminar fracture toughness of the manufactured TP-FMLs with the optimum metal surface treatment were evaluated. The experimental results of the TP-FMLs were compared to an equivalent thermoplastic composite. The composite-metal interface and the fracture surface characteristics were examined under scanning electron microscopy. In-situ polymerisation was found to play a key role in bonding the treated Al alloy with the composite layer during manufacturing

L exposition professionnelle aux produits cancérogènes dans les Pays de la Loire

Objectif : Cibler les populations salariées les plus exposées aux cancérogènes dans les Pays de la Loire, caractériser l exposition professionnelle à ces produits et la comparer à l exposition nationale. Méthode : Exploitation de l enquête SUMER 2003. Réalisation d un calage à la marge de l échantillon qui permet l extrapolation des résultats obtenus sur l échantillon à la population régionale. Comparaison des résultats régionaux aux résultats nationaux. Résultats et discussion : Les hommes sont davantage exposés aux cancérogènes que les femmes. Des différences sociales majeures apparaissent en terme d exposition aux produits cancérogènes : 25,0 % des ouvriers sont exposés à des produits cancérogènes alors que seuls, 4,4 % des salariés des autres catégories socioprofessionnelles le sont. Les moins de 30 ans sont plus exposés que les autres. Parmi les ouvriers exposés, 45% sont exposés à au moins un produit cancérogène avec une intensité élevée. Dans ces situations rencontrées principalement dans la construction et l industrie manufacturière, les protections collectives ne sont présentes que dans 1/3 des situations d exposition et les protections individuelles sont trop peu souvent mises à disposition. L enquête SUMER permet de pointer les difficultés de mise en place de mesures préventives pour lutter contre l exposition aux produits cancérogènes (lorsque la substitution n est pas possible) et d identifier les populations à cibler en priorité pour améliorer cette prévention : les jeunes ouvriers.ANGERS-BU Médecine-Pharmacie (490072105) / SudocSudocFranceF

Consumption Taxes and Corporate Income Taxes: Evidence from Place-Based VAT

Using a quasi-experimental setting, we document that corporations decrease declared profits and corporate income taxes in response to an increase in the VAT rate. In an attempt to raise tax revenue during the Greek economic crisis, a 16% VAT rate, which existed for historicopolitical reasons in Greek islands, was harmonised to the national 24% rate. We combine tax filings with Orbis and ICAP data that enable us to geolocate corporations and to construct comparable groups based on locations in or out of the preferential rate. Counteracting the reform’s intended effect, declared profits decreased by 28% and corporate income taxes by 34% on a permanent basis. Macroeconomic factors and a fall in reported revenue cannot fully explain this decrease. Pervasive tax evasion in the Greek islands, where corporations might have an opportunity to adjust profits, offers a plausible explanation of the magnitude of responses