ABSTRACT
We investigated optical properties of In-flushed InAs quantum dots (QDs) grown on a GaAs substrate by molecular beam epitaxy. By using the In-flush technique for setting the height of self-assembled InAs QDs, we have tuned the emission wavelength of InAs QDs to the ~1 µm regime, which can be utilized as a non-invasive and deeply penetrative probe for biological and medical imaging systems. The controlled emission exhibited a broadband spectrum comprising multiple peaks with an interval of approximately 30 meV. We examined the origin of the multiple peaks using spectral and time-resolved photoluminescence, and concluded that it is attributed to monolayer step fluctuations in the height of the In-flushed QDs. This feature can be advantageous for realizing a broadband light source centered at the ~1 µm regime, which is especially suitable for the non-invasive cross-sectional biological and medical imaging system known as optical coherence tomography.
ABSTRACT
We report an 84-year-old man with perforation caused by emphysematous cholecystitis who showed flare on the skin of the right dorsal lumbar region and intraperitoneal free gas. The patient was admitted for abdominal pain, abdominal swelling, and consciousness disorder 18 days after the onset. Abdominal computed tomography (CT) revealed emphysema in the gallbladder and a small amount of intraperitoneal free gas. Intraoperative findings suggested gangrenous cholecystitis. The gallbladder wall was perforated, and an abscess involving the right subphrenic region, the periphery of the liver and gallbladder, and the right paracolonic groove, was detected. The flare on the body surface may have reflected abscess formation in the right abdominal cavity. Emphysematous cholecystitis induces necrosis and perforation in many patients, and immediate strategies such as emergency surgery are important.