Outflows from active galactic nuclei: The BLR-NLR metallicity correlation

The metallicity of active galactic nuclei (AGNs), which can be measured by emission line ratios in their broad and narrow line regions (BLRs and NLRs), provides invaluable information about the physical connection between the different components of AGNs. From the archival databases of the International Ultraviolet Explorer, the Hubble Space Telescope and the Sloan Digital Sky Survey, we have assembled the largest sample available of AGNs which have adequate spectra in both the optical and ultraviolet bands to measure the narrow line ratio [N II]/H{\alpha} and also, in the same objects, the broad-line N V/C IV ratio. These permit the measurement of the metallicities in the NLRs and BLRs in the same objects. We find that neither the BLR nor the NLR metallicity correlate with black hole masses or Eddington ratios, but there is a strong correlation between NLR and BLR metallicities. This metallicity correlation implies that outflows from BLRs carry metal-rich gas to NLRs at characteristic radial distances of ~ 1.0 kiloparsec. This chemical connection provides evidence for a kinetic feedback of the outflows to their hosts. Metals transported into the NLR enhance the cooling of the ISM in this region, leading to local star formation after the AGNs turn to narrow line LINERs. This post-AGN star formation is predicted to be observable as an excess continuum emission from the host galaxies in the near infrared and ultraviolet, which needs to be further explored.Comment: 19 pages, 13 figures, 3 tables. Accepted for publication at MNRA

Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating

InGaAs/InP single-photon avalanche diodes (SPADs) working in the regime of GHz clock rates are crucial components for the high-speed quantum key distribution (QKD). We have developed for the first time a compact, stable and user-friendly tabletop InGaAs/InP single-photon detector system operating at a 1.25 GHz gate rate that fully integrates functions for controlling and optimizing SPAD performance. We characterize the key parameters of the detector system and test the long-term stability of the system for continuous operation of 75 hours. The detector system can substantially enhance QKD performance and our present work paves the way for practical high-speed QKD applications.Comment: 11 pages, 6 figures. Accepted for publication in Review of Scientific Instrument

1,3-Di-4-pyrid­ylpropane–2-hydroxy­benzene-1,4-dicarboxylic acid (1/2)

In the title compound, C13H14N2·2C8H6O5, which crystallized in the monoclinic C2/c space group, the 1,3-bis­(4-pyrid­yl)propane mol­ecules and 2-hydr­oxy-1,4-benzene­dicarboxylic acid mol­ecules are alternately linked by O—H⋯N and O—H⋯O hydrogen bonds into herringbone/zigzag chains

Autoimmune Response Confers Decreased Cardiac Function in Patients with Rheumatic Mitral Lesion following Valve Replacement

Purpose: To explore the effect of autoimmune response on the decreased cardiac function in patients with rheumatic mitral lesion following valve replacement.Methods: In this case-controlled study, 29 patients who had undergone valve replacement as a result of mitral lesion were enrolled (mean age = 48.7 years). Twenty healthy volunteers were selected as control (mean age = 47.5 years). Plasma levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), high –sensitivity C-reactive protein (hs-CRP) and echocardiographic indices of heart function in the two groups were investigated, respectively. Body mass index (BMI) was also calculated.Results: TNF-α, IL-6 and hs-CRP levels in plasma were significantly higher than those in controls (p < 0.05; 22.23 pg/mL vs. 13.24 pg/mL, 53.42 pg/mL vs. 9.57 pg/mL, and 2.12 μg/mL vs. 0.97 μg/mL, respectively). The indices of left atrial diameter (LAD), left ventricular end-diastolic diameter (LDD) and isovolumetric contraction time (ICT) were significantly higher (p < 0.05; 4.72 cm vs. 3.78 cm, 4.85 cm vs. 4.37 cm, and 76.38 ms vs. 66.24 ms, respectively), but those of early diastolic velocity (Ea), late diastolic velocities (Aa) and ejection time (ET) were significantly lower (p < 0.05; 7.65 cm/s vs. 16.8 cm/s, 5.56 cm/s vs. 12.9 cm/s, and 261.54 ms vs. 276.14 ms, respectively). Two-dimensional echocardiography obtained the same results.Conclusion: Valve replacement in patients with rheumatic heart disease (RHD) does not attenuate inflammatory response; rather, autoimmune response would keep affecting decreased heart function in RHD patients who have received mitral valve replacement.Keywords: Tumor necrosis factor-α, Interleukin-6, High sensitivity C reactive protein, Mitral lesion, Mitral valve replacemen