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    Interatomic and Intermolecular Coulombic Decay
    (Washington, DC : ACS Publ., 2020) Jahnke, Till; Hergenhahn, Uwe; Winter, Bernd; Dörner, Reinhard; Frühling, Ulrike; Demekhin, Philipp V.; Gokhberg, Kirill; Cederbaum, Lorenz S.; Ehresmann, Arno; Knie, André; Dreuw, Andreas
    Interatomic or intermolecular Coulombic decay (ICD) is a nonlocal electronic decay mechanism occurring in weakly bound matter. In an ICD process, energy released by electronic relaxation of an excited atom or molecule leads to ionization of a neighboring one via Coulombic electron interactions. ICD has been predicted theoretically in the mid nineties of the last century, and its existence has been confirmed experimentally approximately ten years later. Since then, a number of fundamental and applied aspects have been studied in this quickly growing field of research. This review provides an introduction to ICD and draws the connection to related energy transfer and ionization processes. The theoretical approaches for the description of ICD as well as the experimental techniques developed and employed for its investigation are described. The existing body of literature on experimental and theoretical studies of ICD processes in different atomic and molecular systems is reviewed. © 2020 American Chemical Society
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    Removing biofilms from microstructured titanium Ex Vivo: A novel approach using atmospheric plasma technology
    (San Francisco, CA : Public Library of Science, 2011) Rupf, S.; Idlibi, A.N.; Marrawi, F.A.; Hannig, M.; Schubert, A.; von Mueller, L.; Spitzer, W.; Holtmann, H.; Lehmann, A.; Rueppell, A.; Schindler, A.
    The removal of biofilms from microstructured titanium used for dental implants is a still unresolved challenge. This experimental study investigated disinfection and removal of in situ formed biofilms from microstructured titanium using cold atmospheric plasma in combination with air/water spray. Titanium discs (roughness (Ra): 1.96 μm) were exposed to human oral cavities for 24 and 72 hours (n = 149 each) to produce biofilms. Biofilm thickness was determined using confocal laser scanning microscopy (n = 5 each). Plasma treatment of biofilms was carried out ex vivo using a microwave-driven pulsed plasma source working at temperatures from 39 to 43°C. Following plasma treatment, one group was air/water spray treated before re-treatment by second plasma pulses. Vital microorganisms on the titanium surfaces were identified by contact culture (Rodac agar plates). Biofilm presence and bacterial viability were quantified by fluorescence microscopy. Morphology of titanium surfaces and attached biofilms was visualized by scanning electron microscopy (SEM). Total protein amounts of biofilms were colorimetrically quantified. Untreated and air/water treated biofilms served as controls. Cold plasma treatment of native biofilms with a mean thickness of 19 μm (24 h) to 91 μm (72 h) covering the microstructure of the titanium surface caused inactivation of biofilm bacteria and significant reduction of protein amounts. Total removal of biofilms, however, required additional application of air/water spray, and a second series of plasma treatment. Importantly, the microstructure of the titanium discs was not altered by plasma treatment. The combination of atmospheric plasma and non-abrasive air/water spray is applicable for complete elimination of oral biofilms from microstructured titanium used for dental implants and may enable new routes for the therapy of periimplant disease.
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    Homopolymerization of ethylene, 1-hexene, styrene and copolymerization of styrene with 1,3-cyclohexadiene using (η5- tetramethylcyclopentadienyl)dimethylsilyl(N-Ar')amido-TiCl2/MAO (Ar'=6-(2-(diethylboryl)phenyl)pyrid-2-yl, biphen-3-yl)
    (Basel : MDPI AG, 2011) Camadanli, S.; Decker, U.; Kühnel, C.; Reinhardt, I.; Buchmeiser, M.R.
    The propensity of a half-sandwich (η55- tetramethylcyclopentadienyl) dimethylsilylamido TiIV-based catalyst bearing an auxiliary diethylboryl-protected pyridyl moiety (Ti-8), activated by methylaluminoxane (MAO) to homopolymerize α-olefins such as ethylene, 1-hexene and styrene as well as to copolymerize styrene with 1,3-cyclohexadiene is described. The reactivity of Ti-8 was investigated in comparison to a 6-(2-(diethylboryl)phenyl)pyrid-2-yl-free analogue (Ti-3).