Element-ratio dependence of the 5d-states of Au and Pt in solid-solution-type Au-Pt alloy nanoparticles studied by X-ray absorption spectroscopy and density functional theory.

Solid-solution-type Au-Pt alloy nanoparticles (NPs) were prepared from the nanoclusters of each metal using the polymer-conjugated fusion growth method. The elemental mapping analysis showed that the mixing state of the elements in the NPs drastically changed in the narrow reaction-temperature range from 100 °C to 180 °C. For their various mixing states, the 5d-states of Au and Pt atoms in the alloy NPs were investigated on the basis of the white line intensities of X-ray absorption near edge structure (XANES). Then, the 5d-states of Au and Pt atoms in a model crystalline ordered alloy structures were investigated on the basis of the theoretically calculated XANES spectra using density functional theory (DFT) in the whole composition range. The DFT calculation showed that the changes in the absorption spectra near the Pt and Au edges are caused by the change in the occupation of the Pt 5d-states and the orbital hybridisation of the Au 5d-states with the 5d-states of neighbouring Pt atoms around an Au atom, respectively.

Correlation between extraocular muscle enlargement and thyroid autoantibodies in thyroid eye disease.

PURPOSE: This study aimed to investigate the factors affecting extraocular muscle enlargement in thyroid eye disease (TED). STUDY DESIGN: Retrospective study. METHODS: The thyroid-stimulating hormone (TSH) receptor antibody (TRAb), thyroid-stimulating antibody (TSAb), antithyroid peroxidase antibody (ATPO), and antithyroglobulin antibody (ATG) levels in patients diagnosed with TED who underwent orbital magnetic resonance imaging were assessed. The control group comprised the contralateral eye of patients who underwent orbital magnetic resonance imaging (MRI) for unilateral eyelid tumors or orbital disease. The thickness of the bilateral rectus muscles and superior oblique muscles was measured on orbital MRI. Muscle enlargement was classified as unilateral/bilateral and symmetric/asymmetric. The effects of age, sex, smoking history, TSH, thyroid hormone, and thyroid autoantibodies on the muscle thickness and number of enlarged muscles were assessed by use of simple and multiple regression analyses. RESULTS: The TED and control groups comprised 41 and 44 cases, respectively. The positivity rate of TSAb in patients with TED was 92.7% higher than that of the other autoantibodies. Muscle enlargement was observed in 29 of the 41 cases (70.7%). Older age and higher TSAb levels were identified as significant factors affecting the total muscle thickness and number of enlarged muscles. Bilateral muscle enlargement and asymmetrical muscle enlargement were observed in 17 (58.6%) and 23 (79.3%) of the 29 cases, respectively. The TSAb levels and age had no significant effect on the type of muscle enlargement. CONCLUSIONS: TSAb showed significant associations with extraocular muscle enlargement. Measurement of TSAb, rather than of TRAb, may be more useful for diagnosing extraocular muscle enlargement in patients with TED.