2,364 research outputs found

    Experimental investigation of the non-Markovian dynamics of classical and quantum correlations

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    We experimentally investigate the dynamics of classical and quantum correlations of a Bell diagonal state in a non-Markovian dephasing environment. The sudden transition from classical to quantum decoherence regime is observed during the dynamics of such kind of Bell diagonal state. Due to the refocusing effect of the overall relative phase, the quantum correlation revives from near zero and then decays again in the subsequent evolution. However, the non-Markovian effect is too weak to revive the classical correlation, which remains constant in the same evolution range. With the implementation of an optical σx\sigma_{x} operation, the sudden transition from quantum to classical revival regime is obtained and correlation echoes are formed. Our method can be used to control the revival time of correlations, which would be important in quantum memory.Comment: extended revision, accepted for publication in Physical Review

    Lensing reconstruction from the cosmic microwave background polarization with machine learning

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    The lensing effect of the cosmic microwave background (CMB) is a powerful tool for our study of the distribution of matter in the universe. Currently, the quadratic estimator (EQ) method, which is widely used to reconstruct lensing potential, has been known to be sub-optimal for the low-noise levels polarization data from next-generation CMB experiments. To improve the performance of the reconstruction, other methods, such as the maximum likelihood estimator and machine learning algorithms are developed. In this work, we present a deep convolutional neural network model named the Residual Dense Local Feature U-net (RDLFUnet) for reconstructing the CMB lensing convergence field. By simulating lensed CMB data with different noise levels to train and test network models, we find that for noise levels less than 5μ5\muK-arcmin, RDLFUnet can recover the input gravitational potential with a higher signal-to-noise ratio than the previous deep learning and the traditional QE methods at almost the entire observation scales.Comment: 12 pages, 8 figures, accepted by Ap

    Mathematical modeling of simultaneous carbon-nitrogen-sulfur removal from industrial wastewater

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    A mathematical model of carbon, nitrogen and sulfur removal (C-N-S) from industrial wastewater was constructed considering the interactions of sulfate-reducing bacteria (SRB), sulfide-oxidizing bacteria (SOB), nitrate-reducing bacteria (NRB), facultative bacteria (FB), and methane producing archaea (MPA). For the kinetic network, the bioconversion of C-N by heterotrophic denitrifiers (NO\ua0→\ua0NO\ua0→\ua0N), and that of C-S by SRB (SO\ua0→\ua0S) and SOB (S\ua0→\ua0S) was proposed and calibrated based on batch experimental data. The model closely predicted the profiles of nitrate, nitrite, sulfate, sulfide, lactate, acetate, methane and oxygen under both anaerobic and micro-aerobic conditions. The best-fit kinetic parameters had small 95% confidence regions with mean values approximately at the center. The model was further validated using independent data sets generated under different operating conditions. This work was the first successful mathematical modeling of simultaneous C-N-S removal from industrial wastewater and more importantly, the proposed model was proven feasible to simulate other relevant processes, such as sulfate-reducing, sulfide-oxidizing process (SR-SO) and denitrifying sulfide removal (DSR) process. The model developed is expected to enhance our ability to predict the treatment of carbon-nitrogen-sulfur contaminated industrial wastewater

    Erratum: A multi-objective optimization-based layer-by-layer blade-coating approach for organic solar cells: Rational control of vertical stratification for high performance (Energy and Environmental Science (2019) 12 (3118-3132) DOI: 10.1039/C9EE02295C)

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    The Acknowledgements section should have included the following sentence: "This work was performed in part on the SAXS/ WAXS beamline at the Australian Synchrotron, part of ANSTO". The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers

    A multi-objective optimization-based layer-by-layer blade-coating approach for organic solar cells:Rational control of vertical stratification for high performance

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    A major breakthrough in organic solar cells (OSCs) in the last thirty years was the development of the bulk heterojunction (BHJ) solution processing strategy, which effectively provided a nanoscale phase-separated morphology, aiding in the separation of Coulombically bound excitons and facilitating charge transport and extraction. Compared with the application of the layer-by-layer (LbL) approach proposed in the same period, the BHJ spin-coating technology shows overwhelming advantages for evaluating the performance of photovoltaic materials and achieving more-efficient photoelectric conversion. Thus, in this study, we have further compared the BHJ and LbL processing strategies via the doctor-blade coating technology because it is a roll-to-roll compatible high-throughput thin film fabrication route. We systematically evaluated multiple target parameters, including morphological characteristics, optical simulation, physical kinetics, device efficiency, and blend stability issues. It is worth emphasizing that our findings disprove the old stereotypes such as the BHJ processing method is superior to the LbL technology for the preparation of high-performance OSCs and the LbL approach requires an orthogonal solvent and donor/acceptor materials with special solubility. Our studies demonstrate that the LbL blade-coating approach is a promising strategy to effectively reduce the efficiency-stability gap of OSCs and even a superior alternative to the BHJ method in commercial applications

    SALL4, a Stem Cell Factor, Affects the Side Population by Regulation of the ATP-Binding Cassette Drug Transport Genes

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    Our previous work shows that the stem cell factor SALL4 plays a central role in embryonic and leukemic stem cells. In this study, we report that SALL4 expression was higher in drug resistant primary acute myeloid leukemic patients than those from drug-responsive cases. In addition, while overexpression of SALL4 led to drug resistance in cell lines, cells with decreased SALL4 expression were more sensitive to drug treatments than the parental cells. This led to our investigation of the implication of SALL4 in drug resistance and its role in side population (SP) cancer stem cells. SALL4 expression was higher in SP cells compared to non-SP cells by 2–4 fold in various malignant hematopoietic cell lines. Knocking down of SALL4 in isolated SP cells resulted in a reduction of SP cells, indicating that SALL4 is required for their self-renewal. The SP phenotype is known to be mediated by members of the ATP-binding cassette (ABC) drug transport protein family, such as ABCG2 and ABCA3. Using chromatin-immunoprecipitation (ChIP), quantitative reverse transcription polymerase chain reaction (qRT-PCR) and electrophoretic mobility shift assay(EMSA), we demonstrated that SALL4 was able to bind to the promoter region of ABCA3 and activate its expression while regulating the expression of ABCG2 indirectly. Furthermore, SALL4 expression was positively correlated to those of ABCG2 and ABCA3 in primary leukemic patient samples. Taken together, our results suggest a novel role for SALL4 in drug sensitivity, at least in part through the maintenance of SP cells, and therefore may be responsible for drug-resistance in leukemia. We are the first to demonstrate a direct link between stem cell factor SALL4, SP and drug resistance in leukemia

    Neuroprotective effect of apocynin nitrone in oxygen glucose deprivation-treated SH-SY5Y cells and rats with ischemic stroke

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    Purpose: To investigate the neuroprotective potential of apocynin nitrone (AN-1), a nitrone analogue of apocynin, in rat brain tissue as a novel candidate for ischemic stroke treatment.Methods: In vitro neuroprotection of AN-1 was studied in SH-SY5Y cells treated with oxygen glucose deprivation (OGD). Cell viability was measured using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2Htetrazolium bromide (MTT) assay, and intracellular reactive oxygen species (ROS) level was investigated using flow cytometry. The protection of AN-1 in cerebral ischemia-reperfusion (I/R) rats was evaluated by cerebral infarct area and neurological deficit score. Oxidative stress of the ischemic hemisphere was assessed by malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) levels.Results: In OGD-treated SH-SY5Y cells, AN-1 reduced cell death and ROS level. In I/R rats, AN-1 exerted potential protection against neurological deficit by reducing infarction area, decreasing neurological deficit score and relieving oxidative stress. AN-1 exhibited stronger action than its parent compound apocynin in vitro, but the two had similar effects in vivo. In addition, AN-1 demonstrated efficacy close to or higher than the positive reference Edaravone® both in vitro and in vivo.Furthermore, AN-1 showed lower toxicity than apocynin in vitro.Conclusion: The results suggest that AN-1 may be a potential neuroprotective agent for the treatment of ischemic stroke in human.Keywords: Apocynin nitrone, Cerebral ischemia-reperfusion injury, Neuroprotection, Reactive oxygen species, Oxidative stres

    Deacetyl­nomilin monohydrate

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    In the title compound (systematic name 1-hy­droxy-1,2-dihydro­obacunoic acid 3,4-lactone monohydrate), C26H32O8·H2O, the dihedral angles between the planes of the ester groups and the furan plane are 43.06 (12) and 56.06 (7)°, while that between the furan plane and the keto group is 58.50 (9)°. The A/B, B/C and C/D ring junctions are all trans-fused. Inter­molecular O—H⋯O hydrogen bonds between the hy­droxy and carbonyl groups and the water mol­ecule give rise to a three-dimensional structure
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