Light and anoxia fading of Prussian blue dyed textiles.

Although Prussian blue is a popular pigment, its stability has been questioned since its discovery in 1704. Its stability upon exposure to light and anoxia remains difficult to apprehend. The present paper focuses on the relative influences of light, anoxia and type of substrate on the discoloration of Prussian blue dyed textiles. Spectrophotometry and X-ray absorption spectroscopy measurements of samples artificially aged by light in air or anoxia show that both the extent of the reduction process at the origin of Prussian blue discoloration and the aging of the textile substrate are linked and strongly differ with the environment. The complex inter-relationship existing between Prussian blue discoloration and textile degradation and the final impact it may have on the conservation of the entire system is discussed

Facteurs influençant l'apparition précoce d'une pneumoconiose chez le mineur de charbon

National audienceL'incidence de la pneumonoconiose a diminue continuellement parmi les mineurs des houilleres pendant les 30 dernieres annees. Actuellement la plupart des cas sont diagnostiques chez les retraites en moyenne vers l'age de 56 ans. Dans ce contexte l'apparition precoce d'une pneumoconiose est un important probleme de sante au travail

Decrease in ovalbumin-induced pulmonary allergic response by benzaldehyde but not acetaldehyde exposure in a guinea pig model

International audienceThe pulmonary effects of two environmentally relevant aldehydes were investigated in non-sensitized or ovalbumin (OA)-sensitized guinea pigs (GPs). Four-week-old male Hartley GPs, weighing about 400 g, were intraperitoneally injected with 1 ml of an NaCl solution containing 100 mug OA and 100 mg Al/(OH)(3). They were then exposed to either acetaldehyde (200 ppb) or benzaldehyde (500 ppb) (or 4 wk (6 h/d, 5 d/wk). At the end of exposure, GPs were challenged with an OA aerosol (0.1% in NaCl) and pulmonary functions were measured. The day after, guinea pigs were anesthetized and several endpoints related to inflammatory anti allergic responses were assessed in blood, whole-lung histology, and bronchoalveolar lavage (BAL). Sensitized nonexposed GPs showed bronchial hyperresponsiveness to OA and an increased number of eosinophils in blood and BAL, together with a rise in total protein and leukotrienes (LTB4 and LTC4/D-4/E-4) in BAL. In nonsensitized GPs, exposure to acetaldehyde or benzaldehyde did not induce any change in the tested parameters;, with the exception of irritation of the respiratory tract as detected by histology and an increased number of alveolar macrophages in animals exposed to acetaldehyde. In sensitized GPs, exposure to acetaldehyde induced a moderate irritation of the respiratory tract but no change in biological parameters linked to the inflammatory and allergic responses, In contrast, exposure to benzaldehyde induced a decrease both in OA-induced bronchoconstriction and in eosinophil and neutrophil numbers in BAL, an increase in the bronchodilatator mediator prostaglandin E-2 (PGE(2)) and a decrease in the bronchoconstrictor mediators LTC4/D-4/E-4. Further investigations are needed to determine if the attenuated response observed in sensitized GPs exposed to benzaldehyde is due to an alteration of the mechanism of sensitization or to a more direct effect on various mechanisms of the allergic response

Epidemiology of pneumoconiosis in coalminers of Nord-Pas-de-Calais in France

This is a longitudinal study of 3 167 active or retired pneumoconiotic coalminers from Nord - Pas de Calais collieries (HBNPC) recognised through medico-legal decision over three defined periods: 1942-61, 1952-81 and 1982-87

Cent scientifiques répliquent à SEA (Suppression des Expériences sur l’Animal vivant) et dénoncent sa désinformation

La lutte contre la maltraitance animale est sans conteste une cause moralement juste. Mais elle ne justifie en rien la désinformation à laquelle certaines associations qui s’en réclament ont recours pour remettre en question l’usage de l’expérimentation animale en recherche

Determinants for the conservation of a vulnerable fire-dependent species at its marginal range

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