Abstract
We present the second release of value-added catalogues of the LAMOST Spectroscopic Survey of the Galactic Anticentre (LSS-GAC DR2). The catalogues present values of radial velocity Vr, ...atmospheric parameters – effective temperature Teff, surface gravity log g, metallicity Fe/H, α-element to iron (metal) abundance ratio α/Fe (α/M), elemental abundances C/H and N/H and absolute magnitudes MV and $M_{K_{\rm s}}$ deduced from 1.8 million spectra of 1.4 million unique stars targeted by the LSS-GAC since 2011 September until 2014 June. The catalogues also give values of interstellar reddening, distance and orbital parameters determined with a variety of techniques, as well as proper motions and multiband photometry from the far-UV to the mid-IR collected from the literature and various surveys. Accuracies of radial velocities reach 5 km s−1 for the late-type stars, and those of distance estimates range between 10 and 30 per cent, depending on the spectral signal-to-noise ratios. Precisions of Fe/H, C/H and N/H estimates reach 0.1 dex, and those of α/Fe and α/M reach 0.05 dex. The large number of stars, the contiguous sky coverage, the simple yet non-trivial target selection function and the robust estimates of stellar radial velocities and atmospheric parameters, distances and elemental abundances make the catalogues a valuable data set to study the structure and evolution of the Galaxy, especially the solar-neighbourhood and the outer disc.
The ataxia-telangiectasia mutated (ATM) protein is a key signaling molecule that modulates the DNA damage response. However, the exact mechanism by which ATM regulates DNA damage repair has not yet ...been elucidated. Here, we report that ATM regulates the DNA damage response by phosphorylating lysine-specific demethylase 2A (KDM2A), a histone demethylase that acts at sites of H3K36 dimethylation. ATM interacts with KDM2A, and their interaction significantly increases in response to DNA double-stranded, but not single-stranded, breaks. ATM specifically phosphorylates KDM2A at threonine 632 (T632) following DNA damage, as demonstrated by a mutagenesis assay and mass spectrometric analysis. Although KDM2A phosphorylation does not alter its own demethylase activity, T632 phosphorylation of KDM2A largely abrogates its chromatin-binding capacity, and H3K36 dimethylation near DNA damage sites is significantly increased. Consequently, enriched H3K36 dimethylation serves as a platform to recruit the MRE11 complex to DNA damage sites by directly interacting with the BRCT2 domain of NBS1, which results in efficient DNA damage repair and enhanced cell survival. Collectively, our study reveals a novel mechanism for ATM in connecting histone modifications with the DNA damage response.
Brain metastasis (BM) is a major cause of mortality in small-cell lung cancer (SCLC) patients; however, the molecular pathway of SCLC BM remains largely unknown because of a lack of investigation. ...Here we screen the levels of some candidate-soluble factors in the serum of SCLC patients and find that SCLC patients with high levels of placental growth factor (PLGF) are prone to BM. Using in vitro blood-brain barrier model, we show that PLGF derived from SCLC cells triggers vascular endothelial growth factor receptor-1-Rho-extracellular regulated protein kinase 1/2 signaling axis activation, results in disassembly of tight junction in brain endothelial cells and promotes SCLC cell transendothelial migration. Furthermore, the downregulation of PLGF suppresses SCLC cell metastasis to the brain in an experimental BM model. These data suggest that PLGF is a potential signature of SCLC BM and a prospective therapeutic target for SCLC BM.
The corrosion behavior of zinc subjected to Liaoning Hongyanhe nuclear power station (a typical coastal-industrial atmospheric environment) has been investigated by weight-loss measurement, scanning ...electron microscopy (SEM) observation, x-ray diffraction (XRD), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The experimental results reveal that the corrosion kinetics of the corrosion of zinc in coastal-industrial atmospheric environment followed empirical equation D = Atn, and with the increase of the exposure time polarization resistance (Rp) and charge transfer resistance (Rct) increased, the corrosion rate decreased gradually. XRD, SEM and EDS indicated that the depth and width of all pits increased with time and the surface corrosion gradually transformed into a uniform corrosion. The components of the rust layers were composed of Zn5(CO3)2 (OH)6, NaZn4SO4Cl(OH)6·6H2O and Zn12(OH)15Cl3(SO4)3·5H2O. In the initial exposure period, the corrosion products was Zn5(CO3)2(OH)6, while with prolonged exposure, a two-layer structured corrosion products formed, which were comprised of NaZn4(SO4)Cl(OH)6·6H2O and Zn12(OH)15Cl3(SO4)3·5H2O, all these products were flaky-structured and compact enough to provide excellent protection.
•A typical coastal-industrial exposure environment.•Zinc corrosion influence the safe and optimal operation of nuclear power plants.•The formation of corrosion products can be divided into two different steps.•The synergy of chloride ion and sulfur dioxide.
We report a successful observation of pressure-induced superconductivity in a topological compound Bi 2 Te 3 with T c of ∼3 K between 3 to 6 GPa. The combined high-pressure structure investigations ...with synchrotron radiation indicated that the superconductivity occurred at the ambient phase without crystal structure phase transition. The Hall effects measurements indicated the hole-type carrier in the pressure-induced superconducting Bi 2 Te 3 single crystal. Consequently, the first-principles calculations based on the structural data obtained by the Rietveld refinement of X-ray diffraction patterns at high pressure showed that the electronic structure under pressure remained topologically nontrivial. The results suggested that topological superconductivity can be realized in Bi 2 Te 3 due to the proximity effect between superconducting bulk states and Dirac-type surface states. We also discuss the possibility that the bulk state could be a topological superconductor.
Generally, in many cases of rock engineering, the openings often constructed in rock-mass containing non-persistent joints. However, comparing with the previous works, few studies investigate the ...failure or damage due to the crack propagation and coalescence around an opening. Based on the uniaxial compression tests and particle flow code (PFC) the interaction effect of opening and joints on the crack coalescence behavior around an opening are investigated in this study. From the view of experimental and numerical results, strength parameters are mainly effected by joints (inclination and distance). Specifically, the uniaxial compressive strength of jointed specimen (UCS
J
) and elastic modulus of jointed specimen (
E
J
) of specimens decrease for 0° ≤
α
≤ 45° and increase for
α
> 45°. UCS
J
and
E
J
increases with increasing joint distance (
d
) for all joint inclination angel (
α
) values, with the highest and lowest strengths obtained for
d
= 50 mm and
d
= 20 mm, respectively. The opening has a great influence on the failure mode of jointed specimen. Unlike previous results, in this study, jointed specimens present four new kinds of failure modes: Mode-I (horizontally symmetrical splitting failure); Mode-II (stepped failure at opening sides); Mode-III (failure through a plane); Mode-IV (mixed failure). The strength parameters and failure modes in the numerically simulated and experimental results are in good agreement, and the results are expected to be useful in predicting the stability of an opening in a non-persistently jointed mass.
Background. The potential for aerosol transmission of infectious influenza virus (ie, in healthcare facilities) is controversial. We constructed a simulated patient examination room that contained ...coughing and breathing manikins to determine whether coughed influenza was infectious and assessed the effectiveness of an N95 respirator and surgical mask in blocking transmission. Methods. National Institute for Occupational Safety and Health aerosol samplers collected size-fractionated aerosols for 60 minutes at the mouth of the breathing manikin, beside the mouth, and at 3 other locations in the room. Total recovered virus was quantitated by quantitative polymerase chain reaction and infectivity was determined by the viral plaque assay and an enhanced infectivity assay. Results. Infectious influenza was recovered in all aerosol fractions (5.0% in >4 μm aerodynamic diameter, 75.5% in 1—4 μm, and 19.5% in <1 μm; n = 5). Tightly sealing a mask to the face blocked entry of 94.5% of total virus and 94.8% of infectious virus (n = 3). A tightly sealed respirator blocked 99.8% of total virus and 99.6% of infectious virus (n = 3). A poorly fitted respirator blocked 64.5% of total virus and 66.5% of infectious virus (n = 3). A mask documented to be loosely fitting by a PortaCount fit tester, to simulate how masks are worn by healthcare workers, blocked entry of 68.5% of total virus and 56.6% of infectious virus (n = 2). Conclusions. These results support a role for aerosol transmission and represent the first reported laboratory study of the efficacy of masks and respirators in blocking inhalation of influenza in aerosols. The results indicate that a poorly fitted respirator performs no better than a loosely fitting mask.
An ethylene‐glycol‐mediated self‐assembly process is adopted to synthesize 3D flowerlike nanostructures of iron oxide (see figure) using inexpensive and nontoxic ferric chloride. A two‐stage growth ...process is identified during the morphological evolution of the iron oxide precursor. α‐Fe2O3, γ‐Fe2O3, and Fe3O4 with the same flowerlike structure are readily obtained from the same precursor but by different calcination procedures. The as‐obtained iron oxides show excellent ability to remove various pollutants from water.
Apoptotic cell death serves as an important tumor suppressor mechanism at multiple steps during cancer progression. Equally, engagement of apoptosis represents a potent therapeutic effector ...mechanism. Nevertheless, the role of apoptosis in cancer may be more complex than previously thought. Indeed, various studies have found that apoptosis signaling also has oncogenic potential. In this review, we discuss how apoptosis can promote cancer and how these effects might be targeted to optimize apoptosis-inducing anticancer therapy.
Extensive efforts have been made to gain a better understanding of the failure behaviour of rocks and rock-like materials, but crack propagation and failure processes under compressive-shear loading ...have not yet been comprehensively investigated. To address this area of research, the peak shear strengths (τ) and failure processes of specimens with multiple joints are studied by lab testing and particle flow code (PFC2D). Four types of failure modes are observed: (a) shear failure through a plane (Mode-I), (b) intact shear failure (Mode-II), (c) oblique shear crack connection failure (Mode-III), and (d) stepped path failure (Mode-IV). The failure mode gradually transformed to Mode-III as α (joint inclination angle) increases from 0° to 90° in the specimens. In addition, with increasing joint distance (
d
) in the specimens, the failure mode changes to Mode-II. As the non-overlapping length between joints (
c
) in the specimens increases, the failure mode changes to Mode-IV. The joint geometry has a major influence on the shear strength of the jointed specimens. The peak shear strength of specimens with different joint inclination angles is obtained when α = 45°. Additionally, the peak shear strength increases as the joint distance (
d
) and non-overlapping length (
c
) increase.
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