....."Many nanoscale materials are regarded as "chemical substances" under the Toxic Substances Control Act (TSCA). This law provides EPA with a strong framework for ensuring that new and existing chemical substances are manufactured and used in a manner that protects against unreasonable risks to human health and the environment. For example, EPA requires manufacturers of new chemical substances to provide specific information to the Agency for review prior to manufacturing chemicals or introducting them into commerce. EPA can require reporting or development of information to assess existing chemicals already in the marketplace. Additionally, EPA can take action to ensure that those chemicals that pose an unreasonable risk to human health or the environment are effectively controlled."..."EPA is launching a collaborative process to design a Nanoscale Materials Stewardship Program under TSCA, to complement and support its efforts on new and existing nanoscale materials."...

"We describe a family of calcium indicators for magnetic resonance imaging (MRI), formed by combining a powerful iron oxide nanoparticle-based contrast mechanism with the versatile calcium-sensing protein calmodulin and its targets. Calcium-dependent protein-protein interactions drive particle clustering and produce up to 5-fold changes in T2 relaxivity, an indication of the sensors' potency. A variant based on conjugates of wild-type calmodulin and the peptide M13 reports concentration changes near 1 µM Ca2+, suitable for detection of elevated intracellular calcium levels. The midpoint and cooperativity of the response can be tuned by mutating the protein domains that actuate the sensor. Robust MRI signal changes are achieved even at nanomolar particle concentrations (<1 µM in calmodulin) that are unlikely to buffer calcium levels. When combined with technologies for cellular delivery of nanoparticulate agents, these sensors and their derivatives may be useful for functional molecular imaging of biological signaling networks in live, opaque specimens."

"Highly luminescent Si quantum dot embedded SiOx films were studied as down-converting emitters for solid-state lighting applications. Strong red photoluminescence was observed from these Si nanocrystal embedded films prepared by thermal evaporation of SiO in vacuum or an O2 atmosphere followed by anneal at 1100 °C. The stoichiometry (1.0<x<1.9) and refractive indices (1.5–1.75) of these films could be well controlled by varying the oxygen flow rate and the deposition rate. The emission peak shifted from 840 to 745 nm with increasing O2 flow rate due to a decrease in the size of the Si QDs. Two excitation bands, peaked at 280 and 370 nm, were observed from these samples. The 370 nm band was much stronger than the 280 nm band, which is near the UV LED emission range required for solid-state lighting applications. Blue and green emissions were also observed from samples annealed at a lower temperature."