814 research outputs found

    A multi-wavelength observation and investigation of six infrared dark clouds

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    Context. Infrared dark clouds (IRDCs) are ubiquitous in the Milky Way, yet they play a crucial role in breeding newly-formed stars. Aims. With the aim of further understanding the dynamics, chemistry, and evolution of IRDCs, we carried out multi-wavelength observations on a small sample. Methods. We performed new observations with the IRAM 30 m and CSO 10.4 m telescopes, with tracers HCO+{\rm HCO^+}, HCN, N2H+{\rm N_2H^+}, C18O{\rm C^{18}O}, DCO+^+, SiO, and DCN toward six IRDCs G031.97+00.07, G033.69-00.01, G034.43+00.24, G035.39-00.33, G038.95-00.47, and G053.11+00.05. Results. We investigated 44 cores including 37 cores reported in previous work and seven newly-identified cores. Toward the dense cores, we detected 6 DCO+^+, and 5 DCN lines. Using pixel-by-pixel spectral energy distribution (SED) fits of the Herschel\textit{Herschel} 70 to 500 μ\mum, we obtained dust temperature and column density distributions of the IRDCs. We found that N2H+{\rm N_2H^+} emission has a strong correlation with the dust temperature and column density distributions, while C18O{\rm C^{18}O} showed the weakest correlation. It is suggested that N2H+{\rm N_2H^+} is indeed a good tracer in very dense conditions, but C18O{\rm C^{18}O} is an unreliable one, as it has a relatively low critical density and is vulnerable to freezing-out onto the surface of cold dust grains. The dynamics within IRDCs are active, with infall, outflow, and collapse; the spectra are abundant especially in deuterium species. Conclusions. We observe many blueshifted and redshifted profiles, respectively, with HCO+{\rm HCO^+} and C18O{\rm C^{18}O} toward the same core. This case can be well explained by model "envelope expansion with core collapse (EECC)".Comment: 24 pages, 11 figures, 4 tables. To be published in A&A. The resolutions of the pictures are cut dow

    Positive-partial-transpose distinguishability for lattice-type maximally entangled states

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    We study the distinguishability of a particular type of maximally entangled states -- the "lattice states" using a new approach of semidefinite program. With this, we successfully construct all sets of four ququad-ququad orthogonal maximally entangled states that are locally indistinguishable and find some curious sets of six states having interesting property of distinguishability. Also, some of the problems arose from \cite{CosentinoR14} about the PPT-distinguishability of "lattice" maximally entangled states can be answered.Comment: It's rewritten. We deleted the original section II about PPT-distinguishability of three ququad-ququad MESs. Moreover, we have joined new section V which discuss PPT-distinguishability of lattice MESs for cases t=3t=3 and t=4t=4 . As a result, the sequence of the theorems in our article has been changed. And we revised the title of our articl

    2-(2-Hy­droxy-3-meth­oxy­phen­yl)-1H-benzimidazol-3-ium perchlorate

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    In the title mol­ecular salt, C14H13N2O2 +·ClO4 −, the ring systems in the cation are almost coplanar [dihedral angle = 5.53 (13)°]. Intra­molecular N—H⋯O and O—H⋯O hydrogen bonds generate S(6) and S(5) rings, respectively. In the crystal, the two H atoms involved in the intra­molecular hydrogen bonds also participate in inter­molecular links to acceptor O atoms of the perchlorate anions. A simple inter­molecular N—H⋯O bond also occurs. Together, these form a double-chain structure along [101]

    Quantifying immediate price impact of trades based on the kk-shell decomposition of stock trading networks

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    Traders in a stock market exchange stock shares and form a stock trading network. Trades at different positions of the stock trading network may contain different information. We construct stock trading networks based on the limit order book data and classify traders into kk classes using the kk-shell decomposition method. We investigate the influences of trading behaviors on the price impact by comparing a closed national market (A-shares) with an international market (B-shares), individuals and institutions, partially filled and filled trades, buyer-initiated and seller-initiated trades, and trades at different positions of a trading network. Institutional traders professionally use some trading strategies to reduce the price impact and individuals at the same positions in the trading network have a higher price impact than institutions. We also find that trades in the core have higher price impacts than those in the peripheral shell.Comment: 6 pages including 3 figures and 1 tabl

    Probing the initial conditions of high-mass star formation -- IV. Gas dynamics and NH2_2D chemistry in high-mass precluster and protocluster clumps

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    The initial stage of star formation is a complex area study because of its high density and low temperature. Under such conditions, many molecules become depleted from the gas phase by freezing out onto dust grains. However, the deuterated species could remain gaseous and are thus ideal tracers. We investigate the gas dynamics and NH2_2D chemistry in eight massive pre/protocluster clumps. We present NH2_2D 111_{11}-101_{01} (at 85.926 GHz), NH3_3 (1, 1) and (2, 2) observations in the eight clumps using the PdBI and the VLA, respectively. We find that the distribution between deuterium fractionation and kinetic temperature shows a number density peak at around Tkin=16.1T_{\rm kin}=16.1 K, and the NH2_2D cores are mainly located at a temperature range of 13.0 to 22.0 K. We detect seven instances of extremely high deuterium fractionation of 1.0Dfrac1.411.0 \leqslant D_{\rm frac} \leqslant 1.41. We find that the NH2_2D emission does not appear to coincide exactly with either dust continuum or NH3_3 peak positions, but often surrounds the star-formation active regions. This suggests that the NH2_{2}D has been destroyed by the central young stellar object (YSO) due to its heating. The detected NH2_2D lines are very narrow with a median width of 0.98±0.02km/s\rm 0.98\pm0.02 km/s. The extracted NH2_2D cores are gravitationally bound (αvir<1\alpha_{\rm vir} < 1), are likely prestellar or starless, and can potentially form intermediate-mass or high-mass stars. Using NH3_3 (1, 1) as a dynamical tracer, we find very complicated dynamical movement, which can be explained by a combined process with outflow, rotation, convergent flow, collision, large velocity gradient, and rotating toroids. High deuterium fractionation strongly depends on the temperature condition. NH2_2D is a poor evolutionary indicator of high-mass star formation in evolved stages, but a useful tracer in the starless and prestellar cores.Comment: 27 pages, 25 figures, 6 tables, accepted for publication in A&

    miRNA-mRNA-protein dysregulated network in COPD in women

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    Rationale: Chronic obstructive pulmonary disease (COPD) is a complex disease caused by a multitude of underlying mechanisms, and molecular mechanistic modeling of COPD, especially at a multi-molecular level, is needed to facilitate the development of molecular diagnostic and prognostic tools and efficacious treatments.Objectives: To investigate the miRNA-mRNA-protein dysregulated network to facilitate prediction of biomarkers and disease subnetwork in COPD in women.Measurements and Results: Three omics data blocks (mRNA, miRNA, and protein) collected from BAL cells from female current-smoker COPD patients, smokers with normal lung function, and healthy never-smokers were integrated with miRNA-mRNA-protein regulatory networks to construct a COPD-specific dysregulated network. Furthermore, downstream network topology, literature annotation, and functional enrichment analysis identified both known and novel disease-related biomarkers and pathways. Both abnormal regulations in miRNA-induced mRNA transcription and protein translation repression play roles in COPD. Finally, the let-7-AIFM1-FKBP1A pathway is highlighted in COPD pathology.Conclusion: For the first time, a comprehensive miRNA-mRNA-protein dysregulated network of primary immune cells from the lung related to COPD in females was constructed to elucidate specific biomarkers and disease pathways. The multi-omics network provides a new molecular insight from a multi-molecular aspect and highlights dysregulated interactions. The highlighted let-7-AIFM1-FKBP1A pathway also indicates new hypotheses of COPD pathology.Peer reviewe

    Ethyl 1-(4-meth­oxy­benz­yl)-3-p-tolyl-1H-pyrazole-5-carboxyl­ate

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    In the title compound, C21H22N2O3, the pyrazole ring makes dihedral angles of 12.93 (8) and 69.38 (8)°, respectively, with the tolyl and meth­oxy­benzyl rings

    Effects of Bufei Yishen formula on klotho gene expression and inflammation-related RIG-I/NF-κB pathway in cigarette smoke extract-treated BEAS-2B cells

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    Purpose: To investigate the anti-inflammatory effect of Bufei yishen formula on chronic obstructive pulmonary disease (COPD) and klotho expression in cigarette smoke extract (CSE)-treated BEAS-2B cells.Methods: Cigarette smoke extract (CSE) was diluted in Dulbecco’s modified Eagle’s medium (DMEM) and used to treat a COPD cell model established using BEAS-2B cells. The CSE-treated cells were transfected with klotho overexpression plasmid, and the COPD cell model was treated with Bufei yishen formula. Dexamethasone was used as positive control. Changes in the expressions of klotho, RIG-I, and NF-ĸB were determined using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, while enzyme linked immunosorbent assay (ELISA) was used to evaluate changes in the expressions of IL-6 and TNF-α.Results: Klotho expression level was reduced in COPD model. Overexpression of klotho inhibited the expressions of IL-6, TNF-α, RIG-I, NF-κB, but bufei yishen formula increased klotho expression level and decreased the expressions of RIG-I, NF-κB, IL-6 and TNF-α. However, after CSE treatment, the anti-inflammatory effect of the formula decreased significantly when klotho expression was knocked down.Conclusion: Bufei yishen formula possesses anti-inflammatory effects which are significantly decreased after klotho knockdown. This suggests that the formula probably acts by upregulating klotho expression, thereby down-regulating the expressions of IL-6 and TNF-α via RIG-I/NF-κB pathway.Keywords: Bufei yishen formula, COPD, Klotho, Inflammation, RIG-I/NF-κ
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