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Novel TiO2 nanoparticles-coated CNTs (TiO2@CNTs) fabricated by the alcohol-thermal method were used as the reinforcement to prepare aluminum matrix composites through high-intensity ultrasonic-assisted casting, followed by heat treatment. The results of optical microscope showed that the optimum heat treatment process was solution treatment (495 °C, 2 h) + aging treatment (180 °C, 12 h). Under this condition, the Al2Cu and Al2CuMg phases were uniformly precipitated in the composites, and most of them were in a discrete state. TEM results revealed that TiO2 nanoparticles dispersed on the surface of CNTs played the role of an interlayer structure between CNTs and matrix, locking the CNTs and improving the CNTs–Al interfacial bonding. The ultimate tensile strength (UTS) and yield strength (YS) of 1.0 wt%TiO2@CNTs/2024 composite after T6 heat treatment reach 324 MPa and 219 MPa, respectively, which exhibited enhanced UTS and YS than the monolithic 2024 alloy. This was attributed to the synergistic strengthening of multi-mechanisms, such as grain refinement strengthening, load transfer strengthening, dislocation strengthening and, especially, Orowan strengthening. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Interestingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01 % CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Additionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream intermediates in the CO signaling responsible for stomatal closure. [ABSTRACT FROM AUTHOR]

Lonicera japonica Thunb, rich in chlorogenic acid (CHA), is used for viral upper respiratory tract infection treatment caused by influenza virus, parainfluenza virus, and respiratory syncytial virus, ect in China. It was reported that CHA reduced serum hepatitis B virus level and death rate of influenza virus-infected mice. However, the underlying mechanisms of CHA against the influenza A virus have not been fully elucidated. Here, the antiviral effects and potential mechanisms of CHA against influenza A virus were investigated. CHA revealed inhibitory against A/PuertoRico/8/1934(H1N1) (EC50 = 44.87 μM), A/Beijing/32/92(H3N2) (EC50 = 62.33 μM), and oseltamivir-resistant strains. Time-course analysis showed CHA inhibited influenza virus during the late stage of infectious cycle. Indirect immunofluorescence assay indicated CHA down-regulated the NP protein expression. The inhibition of neuraminidase activity confirmed CHA blocked release of newly formed virus particles from infected cells. Intravenous injection of 100 mg/kg/d CHA possessed effective antiviral activity in mice, conferring 60% and 50% protection from death against H1N1 and H3N2, reducing virus titres and alleviating inflammation in the lungs effectively. These results demonstrate that CHA acts as a neuraminidase blocker to inhibit influenza A virus both in cellular and animal models. Thus, CHA has potential utility in the treatment of the influenza virus infection. [ABSTRACT FROM AUTHOR]

Key message: By using pharmacological and molecular approaches, we discovered the involvement of HO-1 in NaHS-induced lateral root formation in tomato seedlings. Abstract: Heme oxygenase-1 (HO-1) and hydrogen sulfide (HS) regulate various responses to abiotic stress and root development, but their involvement in the simultaneous regulation of plant lateral root (LR) formation is poorly understood. In this report, we observed that the exogenously applied HS donor sodium hydrosulfide (NaHS) and the HO-1 inducer hemin induce LR formation in tomato seedlings by triggering intracellular signaling events involving the induction of tomato HO- 1 ( SlHO- 1), and the modulation of cell cycle regulatory genes, including the up-regulation of SlCDKA;1 and SlCYCA2;1, and simultaneous down-regulation of SlKRP2. The response of NaHS in the induction of LR formation was impaired by the potent inhibition of HO-1, which was further blocked when 50 % saturation of carbon monoxide (CO) aqueous solution, one of the catalytic by-products of HO-1, was added. Further molecular evidence revealed that the NaHS-modulated gene expression of cell cycle regulatory genes was sensitive to the inhibition of HO-1 and reversed by cotreatment with CO. The impairment of LR density and length as well as lateral root primordia number, the decreased tomato HO- 1 gene expression and HO activity caused by an HS scavenger hypotaurine were partially rescued by the addition of NaHS, hemin and CO (in particular). Together, these results revealed that at least in our experimental conditions, HO-1 might be involved in NaHS-induced tomato LR formation. Additionally, the use of NaHS and hemin compounds in crop root organogenesis should be explored. [ABSTRACT FROM AUTHOR]