Determination of incommensurate modulated structure in Bi2Sr1.6La0.4CuO6+{\delta} by aberration-corrected transmission electron microscopy

Incommensurate modulated structure (IMS) in Bi2Sr1.6La0.4CuO6+{\delta} (BSLCO) has been studied by aberration corrected transmission electron microscopy in combination with high-dimensional (HD) space description. Two images in the negative Cs imaging (NCSI) and passive Cs imaging (PCSI) modes were deconvoluted, respectively. Similar results as to IMS have been obtained from two corresponding projected potential maps (PPMs), but meanwhile the size of dots representing atoms in the NCSI PPM is found to be smaller than that in PCSI one. Considering that size is one of influencing factors of precision, modulation functions for all unoverlapped atoms in BSLCO were determined based on the PPM obtained from the NCSI image in combination with HD space description

Study of B→K∗ρ,K∗ωB\to K^* \rho, K^*\omega Decays with Polarization in Perturbative QCD Approach

The $B \to K^{*}\rho$, $K^{*}\omega$ decays are useful to determine the CKM angle $\phi_3=\gamma$. Their polarization fractions are also interesting since the polarization puzzle of the $B\to \phi K^*$ decay. We study these decays in the perturbative QCD approach based on $k_T$ factorization. After calculating of the non-factorizable and annihilation type contributions, in addition to the conventional factorizable contributions, we find that the contributions from the annihilation diagrams are crucial. They give dominant contribution to the strong phases and suppress the longitudinal polarizations. Our results agree with the current existing data. We also predict a sizable direct CP asymmetries in $B^+ \to K^{*+}\rho^0$, $B^0 \to K^{*+}\rho^-$, and $B^+ \to K^{*+}\omega$ decays, which can be tested by the oncoming measurements in the B factory experiments.Comment: 15 pages, latex, including 4 figure

A Thymidine Kinase recombinant protein-based ELISA for detecting antibodies to Duck Plague Virus

<p>Abstract</p> <p>Background</p> <p>Duck plague virus (DPV) is the causative agent of Duck Plague (DP) that causes significant morbidity and mortality throughout duck-producing areas of the world. The diagnosis of DP currently relies on the use of live or inactivated whole DPV virion as antigens in ELISA, but it is too laborious and expensive for routine application, and it is still difficult to get purified DPV virion with current technology.</p> <p>Results</p> <p>In this study, we describe the expression and purification of a recombinant Thymidine Kinase (TK) protein which makes antigen in an in-house developed, optimized and standardized ELISA. The specificity of the optimized TK-ELISA was evaluated by antisera against Duck Plague Virus (DPV), Duck Hepatitis B Virus (DHBV), Duck Hepatitis Virus (DHV), <it>Riemerella Anatipestifer</it>(<it>R. A</it>), <it>Escherichia coli </it>(<it>E. coli</it>) and <it>Salmonella anatum </it>(<it>S. anatum</it>). Only antisera against DPV yielded a specific and strong signal. In order to determine the sensitivity of the TK-ELISA, a panel of diluted sera was tested, and the minimum detection limit of 1:2560 (OD450 nm = 0.401) was obtained according to the endpoint cut-off (0.2438). The repeatability and reproducibility under the experimental conditions demonstrates a low variability (P > 0.05). The suspected sera samples (n = 30) were determined by TK-ELISA and the positive rate is 90% (27/30), and the TK-ELISA showed 83.33% (22+3/30) coincidence rate with the Serum Neutralization Test (SNT) and 90% (24+3/30) coincidence rate with the whole DPV virion based-ELISA (DPV-ELISA). When defining the dynamics of antibody response to attenuated live DPV vaccine, the maximum antibodies is reached after 4 weeks.</p> <p>Conclusions</p> <p>The results suggest that the TK-ELISA provides high specificity, sensitivity, repeatability and reproducibility for detection of anti-DPV antibodies in duck sera, and has the potential to be much simpler than DPV-ELISA and SNT for the sera epidemiological investigation.</p

Experimental and DFT Studies: Novel Structural Modifications Greatly Enhance the Solvent Sensitivity of Live Cell Imaging Dyes

Structural modifications of previously reported merocyanine dyes (J. Am. Chem. Soc. 2003, 125, 4132–4145) were found to greatly enhance the solvent dependence of their absorbance and fluorescence emission maxima. Density functional theory (DFT) calculations have been performed to understand the differences in optical properties between the new and previously synthesized dyes. Absorption and emission energies were calculated for several new dyes using DFT vertical self-consistent reaction field methods (VSCRF). Geometries of ground and excited states were optimized with a Conductor-like screening model (COSMO) and self-consistent-field (SCF) methods. The new dyes have enhanced zwitterionic character in the ground state, and much lower polarity in the excited state, as shown by the DFT-VSCRF calculations. Consistently, the position of the absorption bands are strongly blue-shifted in more polar solvent (methanol compared to benzene) as predicted by the DFT spectral calculations. Inclusion of explicit H-bonding solvent molecules within the quantum model further enhances the predicted shifts, and is consistent with the observed spectral broadening. Smaller, but significant spectral shifts in polar versus nonpolar solvent are predicted and observed for emission bands. The new dyes show large fluorescence quantum yields in polar hydrogen bonding solvents; qualitatively, the longest bonds along the conjugated chain at the excited S1 state minimum are shorter in the more polar solvent, inhibiting photoisomerization. The loss of photostability of the dyes is a consequence of the reaction with and electron transfer to singlet oxygen, starting oxidative dye cleavage. The calculated vertical ionization potentials of three dyes I-SO, AI-SO(4), and AI-BA(4) in benzene and methanol are consistent with their relative photobleaching rates; the charge distributions along the conjugated chains for the three dyes are similarly predictive of higher reaction rates for AI-SO(4) and AI-BA(4) than for I-SO. Time dependent DFT (TDDFT) calculations were also performed on AI-BA(4); these were less accurate than the VSCRF method in predicting the absorption energy shift from benzene (C6H6) to methanol (MeOH)

Metabolomic profiling combined with network analysis of serum pharmacochemistry to reveal the therapeutic mechanism of Ardisiae Japonicae Herba against acute lung injury

Introduction: Acute lung injury (ALI) is a common and devastating respiratory disease associated with uncontrolled inflammatory response and transepithelial neutrophil migration. In recent years, a growing number of studies have found that Ardisiae Japonicae Herba (AJH) has a favorable anti-inflammatory effect. However, its serum material basis and molecular mechanism are still unknown in ALI treatment. In this study, metabolomics and network analysis of serum pharmacochemistry were used to explore the therapeutic effect and molecular mechanism of AJH against lipopolysaccharide (LPS)-induced ALI.Methods: A total of 12 rats for serum pharmacochemistry analysis were randomly divided into the LPS group and LPS + AJH-treated group (treated with AJH extract 20 g/kg/d), which were administered LPS (2 mg/kg) by intratracheal instillation and then continuously administered for 7 days. Moreover, 36 rats for metabolomic research were divided into control, LPS, LPS + AJH-treated (5, 10, and 20 g/kg/d), and LPS + dexamethasone (Dex) (2.3 × 10−4 g/kg/d) groups. After 1 h of the seventh administration, the LPS, LPS + AJH-treated, and LPS + Dex groups were administered LPS by intratracheal instillation to induce ALI. The serum pharmacochemistry profiling was performed by UPLC-Orbitrap Fusion MS to identify serum components, which further explore the molecular mechanism of AJH against ALI by network analysis. Meanwhile, metabolomics was used to select the potential biomarkers and related metabolic pathways and to analyze the therapeutic mechanism of AJH against ALI.Results: The results showed that 71 serum components and 18 related metabolites were identified in ALI rat serum. We found that 81 overlapping targets were frequently involved in AGE-RAGE, PI3K-AKT, and JAK-STAT signaling pathways in network analysis. The LPS + AJH-treated groups exerted protective effects against ALI by reducing the infiltration of inflammatory cells and achieved anti-inflammatory efficacy by significantly regulating the interleukin (IL)-6 and IL-10 levels. Metabolomics analysis shows that the therapeutic effect of AJH on ALI involves 43 potential biomarkers and 14 metabolic pathways, especially phenylalanine, tyrosine, and tryptophan biosynthesis and linoleic acid metabolism pathways, to be influenced, which implied the potential mechanism of AJH in ALI treatment.Discussion: Our study initially elucidated the material basis and effective mechanism of AJH against ALI, which provided a solid basis for AJH application

LAMOST medium-resolution spectroscopic survey of binarity and exotic star (LAMOST-MRS-B): Observation strategy and target selection

LAMOST-MRS-B is one of the sub-surveys of LAMOST medium-resolution (R~7500) spectroscopic survey. It aims at studying the statistical properties (e.g., binary fraction, orbital period distribution, mass ratio distribution) of binary stars and exotic stars. We intend to observe about 30000 stars (10 mag <= G <= 14.5 mag) with at least 10 visits in five years. We first planned to observe 25 plates around the galactic plane in 2018. Then the plates were reduced to 12 in 2019 because of the limitation of observation. At the same time, two new plates located at the high galactic latitude were added to explore binary properties influenced by the different environments. In this survey project, we set the identified exotic and low-metallicity stars with the highest observation priorities. For the rest of the selected stars, we gave higher priority to the relatively brighter stars in order to obtain high-quality spectra as many as possible. Spectra of 49129 stars have been obtained in LAMOST-MRS-B field and released in DR8, of which 28828 and 3375 stars have been visited more than twice and ten times with SNR >= 10, respectively. Most of the sources are B-, A-, and F-type stars with 0.6 < [Fe/H] < 0.4 dex. We also obtain 347 identified variable and exotic stars and about 250 stars with [Fe/H] < 1 dex. We measure radial velocities (RVs) by using 892233 spectra of the stars. The uncertainties of RV achieve about 1 km/s and 10 km/s1 for 95% of late- and early-type stars, respectively. The datasets presented in this paper are available at http://www.doi.org/10.57760/sciencedb.j00113.00035