Prussian blue (PB) and its analogues are widely studied because of their interesting and promising magnetic and optical properties. The pigment Prussian blue, found in different types of artworks (paintings, watercolors and photographs), is also studied in the area of heritage science, where its capricious fading behavior under light or anoxia treatment poses problematic conservation issues. PB fading is due to the reduction of iron(III) to iron(II) and depends significantly on the artefact. This paper focuses on the roles of the substrate in affecting the PB structure and modifying the redox process. In particular, X-ray absorption experiments at the Fe K-edge of unfaded and faded PB-paper samples show that changes in the PB structure can happen by simple contact with the substrate, prior to the fading treatment. Spectrophotometric measurements on a series of model PB-paper samples further demonstrate the multiple influences of the substrate and show that not only its chemical composition but also its role as a dispersion and textured medium significantly alter the fading behavior of PB. A potential roadmap is proposed to rationally investigate the complex fading process of Prussian blue on a substrate.

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The rural district of the Meuse (East France) has a high number of elderly patients for whom prognosis of ischaemic strokes is poor with high-haemorrhagic transformation risk of intravenous tissue plasminogen activator (rt-PA). This disadvantage is made worse by the distances a patient has to travel to the nearest stroke unit. We set out to assess the effectiveness of a telestroke system implemented in this area. Between October 2010 and February 2012, data from each "tele-expertised" patient were collected. 53 patients were examined. Diagnosis of ischaemic stroke was confirmed in 43 cases (81 %), and intravenous rt-PA treatment performed in 21 cases (40 %). In the treated patient group, median age was 73 years, with 29 % of octogenarians. Baseline National Institutes of Health Stroke Scale (NIHSS) was 16, with 29 % ≥ 20. The median onset to needle time was 169 min, and the median door to needle time was 69 min. Intracranial haemorrhage occurred in 3 cases (14 %), and was symptomatic in two (10 %). At 3 months, median NIHSS was 6, 6 patients (29 %) presented a favourable outcome (modified Rankin scale ≤ 1) and 3 (14 %) had died. In rural areas, for elderly patients with severe ischaemic strokes, telemedicine appears to be a way of improving accessibility and benefits of rt-PA treatment.

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