Dynamic Polymer Free Volume Monitored by Single-Molecule Spectroscopy of a Dual Fluorescent Flapping Dopant.

Single-molecule spectroscopy (SMS) of a dual fluorescent flapping molecular probe (N-FLAP) enabled real-time nanoscale monitoring of local free volume dynamics in polystyrenes. The SMS study was realized by structural improvement of a previously reported flapping molecule by nitrogen substitution, leading to increased brightness (22 times) of the probe. In a polystyrene thin film at the temperature of 5 K above the glass transition, the spectra of a single N-FLAP molecule undergo frequent jumps between short- and long-wavelength forms, the latter one indicating planarization of the molecule in the excited state. The observed spectral jumps were statistically analyzed to reveal the dynamics of the molecular environment. The analysis together with MD and QM/MM calculations show that the excited-state planarization of the flapping probe occurs only when sufficiently large polymer free volume of more than, at least, 280 Å3 is available close to the molecule, and that such free volume lasts for an average of 1.2 s.

Granulomatosis with polyangiitis complicated with refractory optic neuritis and maxillary osteomyelitis.

We report a case of a 61-year-old man with granulomatosis with polyangiitis (GPA) complicated with refractory optic neuritis and maxillary osteomyelitis. He had been treated with prednisolone (PSL) as cryptogenic organizing pneumonia in the respiratory department for 2 years. Afterward, he complained tenderness of paranasal sinuses and rapidly progressive visual loss of the left eye. Although both MPO-ANCA and PR3-ANCA were negative, he was diagnosed as GPA based on the American College of Rheumatology 1990 criteria. Ophthalmologic and oral examination revealed left optic neuritis and destructive maxillary bone. Magnetic resonance imaging (MRI) showed the optic neuritis and inflammation around the optic nerve. This finding suggested that the direct spread of inflammation from paranasal sinuses caused the optic neuritis. In a short time, increasing a dose of PSL and administration of intravenous cyclophosphamide were initiated. Antibiotics were also administered to treat sinusitis. Although his visual acuity of the left eye deteriorated to no light perception temporarily, it finally improved after treatment and findings of MRI were also improved. In contrast, destruction of maxilla bone had been progressing. This is a rare case of GPA complicated with optic neuritis due to sinusitis and maxillary osteomyelitis.