[Inflammatory Polyp due to Peanut Aspiration, Needed to Differentiate from Malignant Tumor: Report of a Case].

The patient was in his 70s. He was addmitted to our hospital because of obstructive pneumonia for 3 months. Chest computed tomography( CT) showed a nodule at the base of the right B8, obstructing the basal branch, with consolidation of the peripheral lung. Bronchoscopy revealed the right basal trunk obstruction by a tumorous lesion. FDG-PET showed heterogeneous FDG uptake at the right hilum and the lower lobe suggesting malignancy, and a thoracoscopic right lower lobectomy was performed. Pathology showed a granulation-like nodule and a brown oval foreign body incarcerated in the peripheral bronchus, which was later revealed to be a peanut, and no obvious malignant findings were observed.

Preparation of Polypropylene-Composite Particles by Dispersion Polymerization.

Polypropylene (PP)/poly(benzyl methacrylate) (PBzMA) composite particles were prepared by dispersion polymerization of benzyl methacrylate (BzMA) in the presence of PP particles without a conventional dispersant. The polymerization process yielded a stable emulsion of composite particles with a "currant bun"-like morphology consisting of a PBzMA core and PP bumps, indicating that the PP particles operate as colloidal stabilizers. Conversely, when BzMA was replaced with styrene as the monomer, dispersion polymerization yielded a large amount of aggregates. Finally, a stable emulsion was formed by copolymerizing a small amount of methyl methacrylate (MMA) with styrene. This result suggested that PP must interact with a second polymer to prepare stable composite particles. The surfaces of the PP particles, which are highly hydrophilic due to their carboxyl groups, were involved in the attachment and stabilization of the polymer precipitated in the medium. A film prepared from the obtained PP/PBzMA composite particles was highly hydrophobic and strongly adhesive to a PP sheet.

Magneto-optical Q-switching using magnetic garnet film with micromagnetic domains.

High-power giant pulses can be used applied in various applications with Q-switched micro-lasers. This method can shorten the pulse duration; however, active control is currently impossible in micro-lasers. To achieve precise pulse control while maintaining compactness and simplicity, we exploit the magneto-optical effect in magnetic garnet films with micromagnetic domains that can be actively controlled by a pulsed magnetic field. Our Q-switching technique enhances the output power by a factor of 4 × 103. Moreover, the device itself is smaller than other Q-switching devices. This novel type of active Q-switch can be combined with a micro-laser to obtain megawatt-order pulses.

Randomly polarised beam produced by magnetooptically Q-switched laser.

Diode-pumped solid-state micro lasers are compact (centimetre-scale), highly stable, and efficient. Previously, we reported Q-switched lasers incorporating rare-earth substituted iron garnet (RIG) film. Here, the first demonstration of the magnetooptical (MO) Q-switch in an Nd:YAG laser cavity is performed. We fabricate a quasi-continuous-wave (QCW) diode-pumped Nd:YAG laser cavity, which is shortened to 10 mm in length and which contains an RIG film and a pair of small coils. This cavity yields a 1,064.58-nm-wavelength pulse with 25-ns duration and 1.1-kW peak power at a 1-kHz repetition ratio. Further, the polarisation state is random, due to the isotropic crystal structure of Nd:YAG and the fact that the MO Q-switch incorporating the RIG film does not require the presence of polarisers in the cavity. This is also the first report of an MO Q-switch producing random polarisation.

Magnetic domains driving a Q-switched laser.

A 10-mm cavity length magnetooptically Q-switched Nd:GdVO4 laser was demonstrated using a single-crystalline ferrimagnetic rare-earth iron garnet film. To design the Q-switching system, the magnetic, optical, and magnetooptical properties of the garnet film were measured. The diode pumped solid-state laser cavity was constructed using a 190-µm-thick garnet film with 58% transmittance. The garnet film had maze-shaped magnetic domains, and the domain walls disappeared when a field of over 200 Oe was applied. Therefore, the polarization state of the transmitted light was modified by modulating the magnetization, and a Q-switched pulse output with a pulse width of 5 ns and peak power of 255 W was achieved in the 10-mm-long cavity. The physical limitation of the pulse width was discussed with the calculated results.