Low threshold current MOVPE grown GaInAs-Al(Ga)InAs separate confinement heterostructure multiquantum well metal-clad ridge-waveguide lasers emitting at 1585 nm
GaInAs-Al(Ga)InAs separate confinement heterostructure (SCH) multiquantum-well (MQW) metal-clad ridge-waveguide (MCRW) laser diodes were successfully fabricated for the first time from layer structures grown by atmospheric pressure (AP) metalorganic vapor-phase epitaxy (MOVPE) on InP substrate without any use of phosphine. CW operation of 2.9- mu m-wide and 400- mu m-long MCRW laser diodes emitting at 1585 nm was demonstrated with a minimum threshold current of 38 mA.<<ETX>>
Conduction Band Edge Discontinuity of In0.52Ga0.48As/In0.52(Ga1-xAlx)0.48As(0≦x≦1) Heterostructures
In0.52Ga0.48As/In0.52(Ga1-xAlx)0.48As/In0.52Ga0.48As potential barrier structures (x=0.25, 0.5, 0.75, 1), lattice-matched to InP, were grown by MBE using a pulsed molecular beam method. The conduction band edge discontinuity, ΔEc(x) between In0.52Ga0.48As and In0.52(Ga1-xAlx)0.48As, was obtained for the first time by measuring the current-voltage characteristics through the barrier structure as a function of temperature in the range of 77–300 K. It was confirmed that the conduction band edge discontinuity varies linearly with Al composition, x, (ΔEc(x)=0.53x(eV) for 0≦x≦1) and is proportional to the band gap difference, ΔEg(x), (ΔEc(x)=0.72ΔEg(x)(eV) for 0≦x≦1).
Thorium-induced Anatomical and Histopathological Changes in Liver of Swiss Mice
ObjectivePresent study is aimed to investigate the anatomical and histopathological changes in liver tissues of Swiss albino male mice, one month after intravenous administration of thorium (232Th; 4 and 40 mg/kg).MethodsSynchrotron X-ray micro-CT imaging, CD31 immuno-cytochemistry, hematoxylin & eosin staining and Periodic acid-Schiff staining were performed to study changes in liver anatomy, blood vessels/capillaries, histology and glycogen content of liver, respectively.ResultsSynchrotron X-ray micro-CT imaging of liver showed loss of blood vessels in mice treated with thorium (4 mg/kg), which was more prominent at higher dose of thorium (40 mg/kg). These thorium-induced changes in liver were correlated with the decrease in CD31 positive cells and loss of tissue architecture. A dose-dependent increase in glycogen content was also observed in the liver of thorium-treated mice.ConclusionOur results provide novel insight about the effects of thorium on liver, which may have significant implications in understanding the mechanism of thorium thorium-induced hepatotoxicity.