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We examined whether galantamine (GAL), a cholinesterase inhibitor and allosteric potentiating ligand for α7 nicotinic acetylcholine receptor (nAChR), had an impact on emotional abnormalities in forebrain-specific cholecystokinin receptor-2 overexpressed transgenic mice. Treatment with GAL (1 mg/kg, s.c.) attenuated the decrease of social interaction time, but failed to attenuate anxiety-like behavior in the elevated plus-maze test. The effect of GAL was blocked by an α7 nAChR antagonist, methyllycaconitine (3 mg/kg, i.p.). These results suggest that GAL improved social interaction impairments via α7 nAChR and could be useful to treat sociability-related emotional abnormalities.

Drain collapse in AlGaN/GaN HFET is analyzed using a two-dimensional device simulator. Two-step saturation is obtained, assuming hole-trap type surface states on the AlGaN surface and a short negative-charge-injected region at the drain side of the gate. Due to the surface electric potential pinning by the surface traps, the negative charge injected region forms a constant potential like in a metal gate region and it acts as an FET with a virtual gate. The electron concentration profile reveals that the first saturation occurs by pinch-off in the virtual gate region and the second saturation occurs by the pinch-off in the metal gate region. Due to the short-channel effect of the virtual gate FET, the saturation current increases until it finally reaches the saturation current of the intrinsic metal gate FET. Current collapses with current degradation at the knee voltage in the I-V characteristics can be explained by the formation of the virtual gate.

The $q$-Painlev\'e equation of type $E^{(1)}_6$ is obtained by Pad\'e method. Special solutions in determinant formula to the $q$-Painlev\'e equation is presented. A relation between Pad\'e method and B\"acklund transformation of type $E^{(1)}_6$ is given., Comment: 23 pages, 2 figures

Side-gating effects on AlGaN/GaN heterojunction FETs (HFETs) are simulated using a two-dimensional device simulator incorporating the Shockley–Read–Hall (SRH) model for deep traps. With the trap parameters obtained from experiments, the simulation results are in agreement with the experimental results including the "half-recovery" from the side-gating effect and the current reduction in the recovery process from positive side-gate bias application. The simulation indicated that the finite thickness of semi-insulating i-GaN layers suppresses side-gating effects on AlGaN/GaN HFETs with thin i-GaN layers.

A GaN Schottky diode with a lateral structure for microwave power rectification was developed on a semi-insulating silicon carbide substrate. Device evaluation showed that the turn-on voltage was around 0.8 V. The on-resistance of the diode with one finger was 25.6 Ω, the breakdown voltages for those with the field plate reached 93 V, for the wafer with a doping level of 4.0 ×1016 cm-3. The forward and reverse characteristics became stabilized after surface etching. RF measurement at 2.45 GHz showed that the capacitance of the diode was about 0.29 pF at a bias of 0 V. The value is satisfactorily small for microwave rectification. If the superior material characteristics of GaN are fully utilized, GaN Schottky diodes will play key roles in microwave power transmission applications.