Gate-controlled amplifiable ultraviolet AlGaN/GaN high-electron-mobility phototransistor.

Gate-controlled amplifiable ultraviolet phototransistors have been demonstrated using AlGaN/GaN high-electron-mobility transistors (HEMTs) with very thin AlGaN barriers. In the AlGaN/GaN HEMTs, the dark current between the source and drain increases with increasing thickness of the AlGaN barrier from 10 to 30 nm owing to the increase in piezoelectric polarization-induced two-dimensional electron gas (2-DEG). However, the photocurrent of the AlGaN/GaN HEMT decreases with increasing thickness of the AlGaN barrier under ultraviolet exposure conditions.

High-performance flat-type InGaN-based light-emitting diodes with local breakdown conductive channel.

Flat-type InGaN-based light-emitting diodes (LEDs) without an n-type contact electrode were developed by using a local breakdown conductive channel (LBCC), and the effect of the In content of the InGaN quantum wells (QWs) on the local breakdown phenomenon was investigated. Electroluminescence and X-ray analyses demonstrated that the homogeneity and crystallinity of the InGaN QWs deteriorated as the In content of the InGaN QWs increased, thereby increasing the reverse leakage current and decreasing the breakdown voltage. After reverse breakdown with a reverse current of several mA, an LBCC was formed on the GaN-based LEDs.

Breakdown-induced conductive channel for III-nitride light-emitting devices.

III-nitride semiconductor-based light-emitting diodes (LEDs) have superior physical properties such as high thermal stability and brightness, for application to solid-state lighting sources. With the commercialization of GaN-based LEDs, improving LED reliability is important because they can be affected by electrostatic discharge, reverse leakage, and breakdown. However, research on the reverse bias characteristics of GaN-based LEDs is insufficient.

Development of a pH indicator composed of high moisture-absorbing materials for real-time monitoring of chicken breast freshness.

A colorimetric bromocresol purple dye-based pH-responsive indicator was developed to monitor the quality of chicken breast meat by direct surface contact. To prevent direct contact of the dye with the chicken breast and to improve its color change sensitivity, it was immobilized with polyvinyl alcohol and a high-absorbance material. The color of the pH indicator changes from yellow to blue and finally purple to indicate spoilage, which can be easily detected by the naked eye.

Disruption of frontal-parietal communication by ketamine, propofol, and sevoflurane.

Introduction: Directional connectivity from anterior to posterior brain regions (or "feedback" connectivity) has been shown to be inhibited by propofol and sevoflurane. In this study the authors tested the hypothesis that ketamine would also inhibit cortical feedback connectivity in frontoparietal networks.

Methods: Surgical patients (n = 30) were recruited for induction of anesthesia with intravenous ketamine (2 mg/kg); electroencephalography of the frontal and parietal regions was acquired.

Total intravenous anesthesia in a 10-month-old patient with congenital myotonic dystrophy undergoing endoscopic third ventriculostomy -A case report-.

Myotonic dystrophy is a rare genetic disorder characterized by muscle atrophy and weakness. Surgical treatment of this condition poses various problems for the anesthesiologist. We describe the anesthetic management of a 10-month-old infant with congenital myotonic dystrophy, who was scheduled for endoscopic third ventriculostomy under general anesthesia.

Comparison of the effects of propofol and pentobarbital on hydrogen peroxide-stimulated hepatic SNU761 cells.

Background: Propofol and barbiturates are both known to protect cells of several organs against ischemia/reperfusion injury, but there are few reports on any possible protective effects on human hepatocytes. We investigated the activities of both agents on human hepatic SNU761 cells under hydrogen peroxide (H(2)O(2))-induced oxidative stress.

Methods: To determine whether propofol and pentobarbital protect hepatocytes from H(2)O(2)-induced toxicity, we used SNU761 cells, a human hepatocellular carcinoma (HCC) cell line.