386 research outputs found

    Controlled Periodic Illumination Enhances Hydrogen Production by over 50% on Pt/TiO2

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    [Image: see text] Efficient solar water photosplitting is plagued by large overpotentials of the HER and OER. Even with a noble metal catalyst, the hydrogen evolution reaction can be limited by the strong M–H bonding over some metals, such as Pt, Pd, and Rh, inhibiting hydrogen desorption. H absorption is regulated by the potential at the metal nanoparticles. Through controlled periodic illumination of a Pt/TiO(2) suspension, we hypothesized a fast variation of the photopotential that induced catalytic surface resonance on the metal, resulting in more than a 50% increase of the efficiency at frequencies higher than 80 Hz

    Impact of Smoking Habit on Peri-Implant Indicators following Different Therapies: A Systematic Review

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    Peri-implant disease and its treatment is becoming a major concern for clinicians as the number of implants placed each year is rising. Smoking is a common habit, and it is associated with an increased risk of developing peri-implant disease. The role of smoking in the response to peri-implant treatment has never been investigated. Searches were conducted in electronic databases to screen articles published until August 2021. The included studies had at least two groups of patients: peri-implant disease only or peri-implant disease and smoking status. Outcomes of interest included plaque index (PI), probing depth (PD), bleeding on probing (BoP), radiographic crestal bone loss (CBL), and analysis of peri-implant sulcular fluid. Seven hundred and forty-nine articles were found in the databases, only 71 articles potentially qualified. A total of seven studies with a minimum follow-up of six months were included. There is no homogeneity in the diagnosis, smoker definition and treatment proposed. All surgical and non-surgical treatment have statistically significantly different outcomes in smokers and nonsmokers. Recognizing this study's limitations, we conclude that smoking might play a significant role on the outcome of peri-implant disease treatment. None of the proposed treatments appear to be significantly more effective

    Formation of hydroxyl radicals by irradiated 1-nitronaphthalene (1NN): oxidation of hydroxyl ions and water by the 1NN triplet state

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    International audienceThe excited triplet state of 1-nitronaphthalene (31NN*) reacts with OH- with a second-order reaction rate constant of (1.66 ± 0.8)¥107 M-1 s-1 (m ± s). The reaction yields the ∑OH radical and the radical anion 1NN-∑. In aerated solution, the radical 1NN-∑ would react with O2 to finally produce H2O2 upon hydroperoxide/superoxide disproportionation. The photolysis of H2O2 is another potential source of ∑OH, but such a pathway would be a minor one in circumneutral (pH 6.5) or in basic solution ([OH-] = 0.3-0.5 M). The oxidation of H2O by 31NN*, with rate constant 3.8 ± 0.3 M-1 s-1, could be the main ∑OH source at pH 6.5
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