3,545 research outputs found
Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating
InGaAs/InP single-photon avalanche diodes (SPADs) working in the regime of
GHz clock rates are crucial components for the high-speed quantum key
distribution (QKD). We have developed for the first time a compact, stable and
user-friendly tabletop InGaAs/InP single-photon detector system operating at a
1.25 GHz gate rate that fully integrates functions for controlling and
optimizing SPAD performance. We characterize the key parameters of the detector
system and test the long-term stability of the system for continuous operation
of 75 hours. The detector system can substantially enhance QKD performance and
our present work paves the way for practical high-speed QKD applications.Comment: 11 pages, 6 figures. Accepted for publication in Review of Scientific
Instrument
MicroRNA-101 Exerts Tumor-Suppressive Functions in Non-small Cell Lung Cancer through Directly Targeting Enhancer of Zeste Homolog 2
Introduction:Overexpression of the enhancer of zeste homolog 2 (EZH2) protein has been found in broad range of cancer types, including non-small cell lung cancer (NSCLC). Nevertheless, the mechanisms by which EZH2 becomes overexpressed in NSCLC remain unclear. MicroRNAs (miRNAs) can regulate target gene expression through translational control. In this study, we investigate whether miRNA (miR-101) regulates EZH2 expression in NSCLC.Methods:We evaluated the expression of miR-101 and EZH2 in 20 matched NSCLC and adjacent nontumor lung tissues by reverse-transcriptase polymerase chain reaction and immunohistochemistry, respectively. Luciferase reporter assay was used to determine whether miR-101 directly targets EZH2. To assess the effect of miR-101 on NSCLC biological behavior, cell proliferation, invasion, and response to chemotherapy were analyzed using NSCLC cells transfected with miR-101 mimics or transfected with specific small interfering RNA to deplete EZH2 (small interfering RNA-EZH2).Results:Reduced expression of miR-101 was associated with overexpression of EZH2 in NSCLC tumor tissues. Transfection of miR-101 mimics significantly suppressed the activity of the luciferase reporter containing wild type but not mutant EZH2 3′-UTR and decreased EZH2 expression in NSCLC cell lines. Furthermore, enforced expression of miR-101 or knockdown of EZH2 led to reduced NSCLC cell proliferation and invasion and sensitized cancer cells to paclitaxel-mediated apoptosis through inducing expression of the proapoptotic protein Bim.Conclusions:miR-101 inhibits cell proliferation and invasion and enhances paclitaxel-induced apoptosis in NSCLC cells, at least in part, by directly repressing EZH2 expression. Therapeutic strategies to rescue miR-101 expression or silence EZH2 may be beneficial to patients with NSCLC in the future
Orbital density wave induced by electron-lattice coupling in orthorhombic iron pnictides
In this paper we explore the magnetic and orbital properties closely related
to a tetragonal-orthorhombic structural phase transition in iron pnictides
based on both two- and five-orbital Hubbard models. The electron-lattice
coupling, which interplays with electronic interaction, is self-consistently
treated. Our results reveal that the orbital polarization stabilizes the spin
density wave (SDW) order in both tetragonal and orthorhombic phases. However,
the ferro-orbital density wave (F-ODW) only occurs in the orthorhombic phase
rather than in the tetragonal one. Magnetic moments of Fe are small in the
intermediate Coulomb interaction region for the striped antiferromangnetic
phase in the realistic five orbital model. The anisotropic Fermi surface in the
SDW/ODW orthorhombic phase is well in agreement with the recent angle-resolved
photoemission spectroscopy experiments. These results suggest a scenario that
the magnetic phase transition is driven by the ODW order mainly arising from
the electron-lattice coupling.Comment: 21 pages, 10 figure
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