Synthesis of 2-Difluoroethylated 2-1,3-Benzoxazines via Proton-Mediated Ring Opening/Interrupted Ritter Reaction of 1,1-Difluorocyclopropanes.

2-(1,1-Difluoroethyl)-2-1,3-benzoxazines were synthesized by (i) the regioselective ring opening of 1,1-difluorocyclopropanes bearing an aryloxy group and (ii) the Ritter reaction followed by a Friedel-Crafts-type ring closure. When 2-aryloxy-1,1-difluorocyclopropanes were treated with triflic acid, the C-C bond distal to the CF moiety was cleaved regioselectively via protonation to generate the corresponding oxocarbenium ions. These intermediates readily underwent nucleophilic attack by nitriles, followed by a carbocationic cyclization to afford the 2-difluoroethylated benzoxazines.

Twenty-four-hour continuous and remote monitoring of respiratory rate using a medical radar system for the early detection of pneumonia in symptomatic elderly bedridden hospitalized patients.

Respiratory rate is often measured manually and discontinuously by counting of chest wall movements in routine clinical practice. We introduce a novel approach to investigate respiration dynamics using a noncontact medical radar system for identifying patient at risk of infection. The system enables early detection of pneumonia in bedridden hospitalized patients.

High-Contrast Imaging of Intermediate-Mass Giants with Long-Term Radial Velocity Trends.

A radial velocity (RV) survey for intermediate-mass giants has been operated for over a decade at Okayama Astrophysical Observatory (OAO). The OAO survey has revealed that some giants show long-term linear RV accelerations (RV trends), indicating the presence of outer companions. Direct imaging observations can help clarify what objects generate these RV trends.

Near-infrared imaging polarimetry of LkCa 15: A possible warped inner disk.

We present high-contrast -band polarized intensity images of the transitional disk around the young solar-like star LkCa 15. By utilizing Subaru/HiCIAO for polarimetric differential imaging, the angular resolution and the inner working angle reach 007 and = 0″.1, respectively.

Measurement of complex amplitude with a point-diffraction interferometer.

We propose a pupil-plane wavefront sensor to measure instantaneous phase and amplitude aberrations, developing the configuration of the point-diffraction interferometer proposed by Imada et al. [Appl. Opt.

Real-time point-diffraction interferometer and its analytical formulation.

We propose a novel wavefront sensor and study its performance with an analytical formulation. The sensor has a polarizing point-diffraction beam splitter. Using transmitted and reflected beams, we can build a real-time point-diffraction interferometer with high precision and efficiency.