914 research outputs found

    Quantum Cloning Machines and the Applications

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    No-cloning theorem is fundamental for quantum mechanics and for quantum information science that states an unknown quantum state cannot be cloned perfectly. However, we can try to clone a quantum state approximately with the optimal fidelity, or instead, we can try to clone it perfectly with the largest probability. Thus various quantum cloning machines have been designed for different quantum information protocols. Specifically, quantum cloning machines can be designed to analyze the security of quantum key distribution protocols such as BB84 protocol, six-state protocol, B92 protocol and their generalizations. Some well-known quantum cloning machines include universal quantum cloning machine, phase-covariant cloning machine, the asymmetric quantum cloning machine and the probabilistic quantum cloning machine etc. In the past years, much progress has been made in studying quantum cloning machines and their applications and implementations, both theoretically and experimentally. In this review, we will give a complete description of those important developments about quantum cloning and some related topics. On the other hand, this review is self-consistent, and in particular, we try to present some detailed formulations so that further study can be taken based on those results.Comment: 98 pages, 12 figures, 400+ references. Physics Reports (published online

    Pre-pregnancy body mass index, height and physical activity are associated with rate of gestational weight gain among Malaysian mothers

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    Aim: Both inadequate and excessive weight gain during pregnancy can have immediate and long-term health risks for women and infants. This study investigated rate of gestational weight gain (GWG) and its associated factors in Malaysian pregnant women. Methods: This cross-sectional study was conducted at maternal and child health clinics in Selangor and Negeri Sembilan between November 2010 and April 2012. A pre-tested questionnaire was used to obtain sociodemographic, obstetric, dietary intake and physical activity information. Current weight and height were measured using standard procedures. GWG rate was calculated as the average weekly weight gain in that particular trimester of pregnancy and further categorized according to the Institute of Medicine (IOM) recommendations. Results: Mean GWG rate for all pre-pregnancy BMI categories in the second and third trimesters was higher than the IOM recommendations. Overweight women (adjusted OR, 4.26; 95%CI: 1.92–9.44) and women <153 cm tall (adjusted OR, 1.96; 95%CI: 1.21–3.18) tend to have inadequate GWG rate. Women with high pre-pregnancy body mass index (BMI; ≥25.0 kg/m2; overweight: adjusted OR, 3.88; 95%CI: 2.12–7.09; obese: adjusted OR, 2.34; 95%CI: 1.28–4.29) and low physical activity (adjusted OR, 1.74; 95%CI: 0.77–3.97) were two–threefold more likely to have excessive GWG. Conclusion: Both inadequate and excessive GWG can have detrimental effects on the health of mothers and infants. Pre-pregnancy BMI, height and physical activity should be emphasized in prenatal care to ensure that women have adequate GWG rate

    (5-Bromo-2-methyl­phen­yl)(4-eth­oxy­phen­yl)methanone

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    In the title compound, C16H15BrO2, the dihedral angle between the benzene rings is 68.5 (2)°. In the crystal structure, mol­ecules are linked by weak C—H⋯O hydrogen bonds into chains parallel to the b axis

    Inhibitory Effect of Curcumol on Jak2-STAT Signal Pathway Molecules of Fibroblast-Like Synoviocytes in Patients with Rheumatoid Arthritis

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    Hyperplasia of synovial membrane in rheumatoid arthritis (RA) is a critical pathological foundation for inducing articular injury. The janus kinase and signal transducer and activator of transcription (Jak-STAT) pathway plays a critical role in synovial membrane proliferation induced by platelet-derived growth factor (PDGF). To explore the anti-cell proliferation mechanism of curcumol, a pure monomer extracted from Chinese medical plant zedoary rhizome, the changes of Jak2-STAT1/3 signal pathway-related molecules in synoviocytes were observed in vitro. In this study, the fibroblast-like synoviocytes (FLS) in patients with RA were collected and cultured. The following parameters were measured: cell proliferation (WST-1 assay), cell cycles (fluorescence-activated cell sorting, FACS), STAT1 and STAT3 activities (electrophoretic mobility shift assay, EMSA), and the protein expressions of phosphorylated Jak2, STAT1, and STAT3 (Western blot). It was shown that curcumol could inhibit the RA-FLS proliferation and DNA synthesis induced by PDGF-BB in a dose-dependent manner in vitro. The transcription factors activities of STAT1 and STAT3 were obviously elevated after PDGF-BB stimulation (P < 0.05). Super-shift experiments identified the STAT1 or STAT3 proteins in the complex. Furthermore, the different concentration curcumol could downregulate the DNA binding activities of STAT1 and STAT3 (P < 0.05) and inhibit the phosphorylation of Jak2 while it had no effect on the protein expressions of STAT1 and STAT3. Positive correlations were found between changes of cell proliferation and DNA-binding activities of STAT1 and STAT3, respectively (P < 0.01). In conclusion, curcumol might suppress the FLS proliferation and DNA synthesis induced by PDGF-BB through attenuating Jak2 phosphorylation, downregulating STAT1 and STAT3 DNA-binding activities, which could provide theoretical foundation for clinical treatment of RA

    A Search for Double-peaked narrow emission line Galaxies and AGNs in the LAMOST DR1

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    LAMOST has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line (NEL) galaxies and AGNs. The double-peaked narrow-line profiles can be well modeled by two velocity components, respectively blueshifted and redshifted with respect to the systemic recession velocity. This paper presents 20 double-peaked NEL galaxies and AGNs found from LAMOST DR1 using a search method based on multi-gaussian fit of the narrow emission lines. Among them, 10 have already been published by other authors, either listed as genuine double-peaked NEL objects or as asymmetric NEL objects, the remaining 10 being first discoveries. We discuss some possible origins for double-peaked narrow-line features, as interaction between jet and narrow line regions, interaction with companion galaxies and black hole binaries. Spatially resolved optical imaging and/or follow-up observations in other spectral bands are needed to further discuss the physical mechanisms at work.Comment: 17 pages, 5figures, 4 tables, accepted by RA
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