Applying validated in vitro assays to the study of nanoparticle toxicity is a growing trend in nanomaterial risk assessment. Precise characterisation of reference nanomaterials and a well-regulated in vitro testing system are required to determine the physicochemical descriptors which dictate the toxic potential of nanoparticles. The use of automated, high-throughput technologies to facilitate the identification and prioritisation of nanomaterials which could pose a risk is desirable and developments are underway. In this study, two mammalian fibroblast lines (Balb/c 3T3 and COS-1 cells) were treated with a range of concentrations of iron oxide nanomaterials manufactured for use in medical diagnostics, using an automated platform and high-content-imaging endpoints for cell viability, oxidative stress and DNA damage (double-strand breaks). At the same time, the high-throughput comet assay was employed to measure DNA strand breaks and oxidised bases. Our results show that these methods provide a fast way to determine the toxicity of coated and uncoated iron oxide nanoparticles and, furthermore, to predict the mechanism of toxicity in vitro.

Despite the existence of several possible pyrometric methodologies, temperature monitoring and control of samples heated at the focus of solar concentrators have still not received a universal and perfect solution. Here we present an analysis of solar-blind conditions and experimental measurements that have been carried out at the Odeillo Solar Furnace (IMP-CNRS). The aim here is to test different experimental configurations that can conceptually eliminate the reflected part of the concentrated solar flux. These configurations would allow near solar-blind measurements within the atmospheric absorption bands centered at 1.4 μm and 1.9 μm, and true solar-blind measurements within similar bands centered at 2.7 μm, 4.3 μm, and 6 μm. The parasitic reflected solar flux can be evaluated for each of these bands. In the case of alumina in particular, true solar-blind measurements can also be performed under blackbody conditions over the 8–12 μm band, and this is taken here as a convenient example of application. It is also demonstrated that solar-blind measurements are possible outside of these absorption bands, either by adding an appropriate radiation cutting filter (e.g., a quartz window) or by using an infrared narrow filter centered in a spectral region where the incident flux is negligible due to reflection losses (e.g., at 3.9 μm). The Solar Performance Factor is introduced to characterize the potential of any spectral region vis-a`-vis solar blindness.

Devices and methods are presented in which an optical fiber reflectometer and a solar concentrator are used to determine solar reflectivity and absorptivity for opaque and diffuse materials. The measurements can be taken at high temperature, the final aim is to reach 2500°C. Firstly we will present the specific reflectometer and its measurement principles. We will then describe the whole experimental hardware (solar concentrator, associated devices) and the method used to determine solar reflectivity and absorptivity. Finally, we will present examples of results obtained on a metallic sample.

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