Efficient Fabrication of Quartz Glass Using Laser Coaxial Powder-Fed Additive Manufacturing Approach.

This article investigates a laser-directed energy deposition additive manufacturing (AM) method, based on coaxial powder feeding, for preparing quartz glass. Through synergistic optimization of line deposition and plane deposition experiments, key parameters of laser coaxial powder feeding AM were identified. The corresponding mechanical properties, thermal properties, and microstructure of the bulk parts were analyzed. The maximum mechanical strength of the obtained quartz glass element reached 72.36 ± 5.98 MPa, which is ca. 95% that of quartz glass prepared by traditional methods. The thermal properties of the obtained quartz glass element were also close to those prepared by traditional methods. The present research indicates that one can use laser AM technology that is based on coaxial powder feeding to form quartz glass with high density and good thermodynamic properties. Such quartz glass has substantial potential in, for example, optics and biomedicine.

Short- and long-term efficacy and safety of triple vs. dual antithrombotic therapy in patients with drug-eluting stent implantation and an indication for oral anticoagulation: a meta-analysis.

BACKGROUND: The optimal antithrombotic regimen after coronary stenting in patients taking oral anticoagulants (OACs) is still unclear. Therefore, this meta-analysis focused on the short- and long-term efficacy and safety of triple therapy (TT: OAC, aspirin, and thienopyridine) and dual therapy (DT: OAC plus single antiplatelet drug or aspirin plus thienopyridine). METHODS: We searched PubMed, Embase, the Cochrane Library, Wangfang database, and Google Scholar up to December 1, 2015 (January 1, 2000 - December 2015), from randomized and nonrandomized studies comparing TT and DT in patients with OACs undergoing drug-eluting stent (DES) implantation. Major adverse cardiac and cerebrovascular events (MACCE) were the main outcome. Safety outcome was major bleeding (MB). RESULTS: Of 964 publications identified, 1 randomized study and 27 nonrandomized studies of 31,346 patients were included. Overall, TT and OAC plus clopidogrel were associated with a lower risk of MACCE, stroke, MI, and allcause mortality compared with dual antiplatelet therapy or OAC plus aspirin. Additionally, short-term use of triple antithrombotic regimen with OAC, aspirin, and clopidogrel is associated with equivalent risk of major bleeding and decreased rate of MACCE. Long-term use of OAC plus clopidogrel after TT was associated with equal or better benefit and safety outcomes. CONCLUSION: For patients on OAC after coronary stenting, triple therapy (OAC, aspirin, clopidogrel) should be considered in the short term, followed by more long-term therapy with OAC plus clopidogrel. More randomized studies are needed to confirm these findings.

[Synthesis of PANI/TiO3 nanorods composites by reverse micelle template and their properties].

PANI/TiO2 nano-composites with different amount of nanometer TiOz were synthesized by using reverse micelle formed from cationic surfactant cetyltrimethyl ammonium bromide (CTAB) as the template. The structure and properties of PANI/TiO2 nano-composites were investigated by FTIR, UV-Vis, TG, TEM and photoluminescence spectroscopy. The self-assembly mechanism of PANI/TiO2 nanorods composites in reversed micelle was discussed briefly. The results indicate that the synthesized nano-composites are PANI/TiO2 nanorods with an average diameter and length around 30-40 nm and 400 nm respectively. The infrared spectrum shows that a strong interaction exists between PANI and TiO2 nano-particles. The thermal stability of PANI/TiO2 nanorods improves with the contents of TiO2 increasing. The absorption of PANI/TiO2 nano-composites was found to be very intense in the range of violet and visible light by UV-Vis spectrum. The fluorescence of PANI/TiO2 nanorods was excited at 416 nm, and the intensity of fluorescence was strengthened greatly with increasing TiO2 concentration. The mechanism of the strengthened fluorescence quantum efficiency and fluorescence intensity of PANI/TiO2 was investigated through the charge transfer and exciton dissociation in PANI/TiO2 nanorods composites.

[Photophysical properties of poly (2-methoxy-5-octyloxy)-p-phenylene vinylene/TiO2 nano-composites].

The photoelectric composites of poly (2-methoxy-5-octyloxy)-p-phenylene vinylene/nanometer TiO2 (PMOCOPV/ TiO2) with different nanometer TiOz amount were synthesized through dehydrochlorination in-situ polymerization. The results of Fourier transform infrared spectroscopy and Raman spectroscopy indicated that the surface of nanometer TiO2 was coated with PMOCOPV. UV-Vis spectrum showed that the absorption of PMOCOPV/TiO2 nano-composites was strengthened in the range of violet and visible light with the contents of TiO2 increasing. The composite dimensions were observed by highly resolution transmission electron microscope, PMOCOPV/TiO2 nano-composites dispersed uniformly and possessed core-shell structure, the diameter of PMOCOPV/TiO2 was measured to be about 30 nm, and the thickness of the PMOCOPV coating was about 8-10 nm. Photoluminescence spectroscopy indicated that the maximum emission wavelength of the PMOCOPV/TiO2 was red-shifted with increasing TiO2 concentration. The fluorescence lifetime of PMOCOPV/TiO2 was about 1 ns. The intensity and lifetime of fluorescence was increased remarkably with the contents of TiO2 increasing. The mechanism of the strengthened fluorescence quantum efficiency and fluorescence intensity of PMOCOPV/TiO2 was investigated through the charge transfer, exciton dissociation and potential energy in PMOCOPV/TiO2 nano-composites.