High power and long lifetime have been demonstrated for a semiconductor quantum-dot (QD) laser with five-stacked InAs/GaAs QDs separated by an InGaAs strain-reducing layer (SRL) and a GaAs spacer layer as an active medium. The QD lasers exhibit a peak power of 3.6 W at 1080 nm, a quantum slope efficiency of 84.6%, and an output-power degradation rate of 5.6%/1000 h with continuous-wave constant-current operation at room temperature. A comparative reliability investigation indicates that the lifetime of the InAs/GaAs QD laser with the InGaAs SRL is much longer than that of a QD laser without the InGaAs SRL. This improved lifetime of the QD laser could be explained by the reduction of strain in and around InAs QDs induced by the InGaAs SRL.

Outer membrane proteins (OMPs) represent an important class of proteins that are observed in gram-negative bacteria, mitochondria and chloroplasts. These proteins play diverse biological roles in protein translocation, cell-cell communication and signal transduction. A variety of OMPs have been identified in the gastrointestinal pathogen Helicobacter pylori (H. pylori) since it was first isolated in 1983. Among these proteins, outer membrane inflammatory protein A (OipA), which is encoded by hopH and unique to this pathogen, is a differentially expressed outer membrane protein that has been confirmed to be directly linked to H. pylori colonization, as well as to the pathogenesis of H. pylori and disease outcome. In this review, we will describe the progress of recent studies on OipA, particularly those on the functions and biological significance of this unique protein.

PbS clusters in zeolite-Y have been prepared with the reaction of Pb2+-ion-exchanged zeolite-Y with Na2S in solution at room temperature. Their absorption spectra show dramatic blue shifts from that of the bulk PbS. Obvious change of both the absorption edges and peak positions upon PbS concentrations have been observed. These phenomena provide evidences that PbS clusters have been formed within the zeolite. The absorption spectra show featureless structure and have no tails near the absorption edges. As the PbS loading density becomes higher, the absorption bands become stronger and sharpen. Order PbS clusters lattice with high quality might be formed in the supercages of zeolite-Y.