results for au:Hall_A in:physics
This work exploits the zeptoliter sensing volume of electrolyte-filled nanopores to determine, simultaneously and in real time, the approximate shape, volume, charge, rotational diffusion coefficient, and dipole moment of individual proteins. We have developed the theory for a quantitative understanding and analysis of modulations in ionic current that arise from rotational dynamics of single proteins as they move through the electric field inside a nanopore. The resulting multi-parametric information raises the possibility to characterize, identify, and quantify individual proteins and protein complexes in a mixture. This approach interrogates single proteins in solution and determines parameters such as the approximate shape and dipole moment, which are excellent protein descriptors and cannot be obtained otherwise from single protein molecules in solution. Taken together, this five-dimensional characterization of biomolecules at the single particle level has the potential for instantaneous protein identification, quantification, and possibly sorting with implications for structural biology, proteomics, biomarker detection, and routine protein analysis.
The UK has no research nuclear reactors and relies on the importation of 99Mo and other medical radioisotopes (e.g. Iodine-131) from overseas (excluding PET radioisotopes). The UK is therefore vulnerable not only to global shortages, but to problems with shipping and importation of the products. In this context Professor Erika Denton UK national Clinical Director for Diagnostics requested that the British Nuclear Medicine Society lead a working group with stakeholders including representatives from the Science & Technology Facilities Council (STFC) to prepare a report. The group had a first meeting on 10 April 2013 followed by a working group meeting with presentations on 9th September 2013 where the scope of the work required to produce a report was agreed. The objectives of the report are: to describe the status of the use of medical radioisotopes in the UK; to anticipate the potential impact of shortages for the UK; to assess potential alternative avenues of medical radioisotope production for the UK market; and to explore ways of mitigating the impact of medical radioisotopes on patient care pathways. The report incorporates details of a visit to the Cyclotron Facilities at Edmonton, Alberta and at TRIUMF, Vancouver BC in Canada by members of the report team.
The excitation of multiple SPP waves as Floquet harmonics was demonstrated in structures fabricated as one-dimensional photonic crystals (PCs) on top of two-dimensional gold gratings. Each period of the PC comprised nine layers of silicon oxynitrides of different compositions, and each PC had either two or three periods. Absorptances for obliquely incident $p$- and $s$-polarized light were measured in the 500--1000-nm wavelength regime and the sharp bands in the absorptance spectra were compared with the solutions of the underlying canonical boundary-value problem. The excitation of multiple surface-plasmon-polariton (SPP) waves as Floquet harmonics was confirmed. The structures demonstrated broadband absorption with overall weak dependences on the incidence angle and the polarization state of the incident light, and has potential application for harvesting solar energy.