Estimation of minimum detectable sample concentrations obtained with near and middle infrared detectors for infrared absorption spectrophotometry

An expression is given to allow estimation of the minimum detectable sample concentration of a molecular absorber measured by any infrared spectrophotometer using photon or thermal detectors. Typical plots are given of minimum detectable sample concentration vs. wavelength for a hypothetical absorber with a molar absorptivity of unity and for several different photon and thermal detectors. Such plots, used along with the general expression, are useful for selecting the optimum detector for a given infrared measurement and for estimation of the minimum detectable sample concentration measured by a specific spectrometric system.     

Magnetic structure of NdB6

Neutron diffraction measurements were made on a polycrystalline sample of NdB₆ at 78 and 4.2 K. This material orders antiferromagnetically with a Neel temperature of 8.6 K. The magnetic structure inferred from the diffraction data indicates a simple antiferromagnetic doubling of the unit cell in one direction. Based on this structure a profile analysis of the data gives a magnetic moment at 4.2 K of 1.74 Bohr magnetons per neodymium ion.     

Nuclear Uptake of Gold Nanoparticles Deduced Using Dual‐Angle X‐Ray Fluorescence Mapping

Studies into the cell nucleus' incorporation of gold nanoparticles (AuNPs) are often limited by ambiguities arising from conventional imaging techniques. Indeed, it is suggested that to date there is no unambiguous imaging evidence for such uptake in whole cells, particularly at the single nanoparticle level. This shortcoming in understanding exists despite the nucleus being the most important subcellular compartment in eukaryotes and gold being the most commonly used metal nanoparticle in medical applications. Here, dual‐angle X‐ray flouresence is used to show individually resolved nanoparticles within the cell nucleus, finding them to be well separated and 79% of the intranuclear population to be monodispersed. These findings have important implications for nanomedicine, illustrated here through a specific exemplar of the predicted enhancement of radiation effects arising from the observed AuNPs, finding intranuclear dose enhancements spanning nearly five orders of magnitude.