The periodontium is an integrated, functional unit of multiple tissues surrounding and supporting the tooth, including but not limited to cementum (CM), periodontal ligament (PDL) and alveolar bone (AB). Periodontal tissues can be destructed by chronic periodontal disease, which can lead to tooth loss. In support of the treatment for periodontally diseased tooth, various biomaterials have been applied starting as a contact inhibition membrane in the guided tissue regeneration (GTR) that is the current gold standard in dental clinic. Recently, various biomaterials have been prepared in a form of tissue engineering scaffold to facilitate the regeneration of damaged periodontal tissues. From a physical substrate to support healing of a single type of periodontal tissue to multi-phase/bioactive scaffold system to guide an integrated regeneration of periodontium, technologies for scaffold fabrication have emerged in last years. This review covers the recent advancements in development of scaffolds designed for periodontal tissue regeneration and their efficacy tested in vitro and in vivo . Pros and Cons of different biomaterials and design parameters implemented for periodontal tissue regeneration are also discussed, including future perspectives.

Electronic properties of 6 nm (HfO2)x(SiO2)1−x dielectric thin films, deposited on Si(100) by atomic layer deposition with x equal to 0.75 and 0.25, were studied by means of x-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). XPS measurements confirmed the formation of a silicate structure, and showed shifts of the Hf 4f and Si 2p peaks with varying Hf concentrations; these shifts are believed to be caused by changes in the amount of charge transfer and by the substitution of Si by Hf as second-nearest-neighbors. The band gap, Eg, was estimated from REELS. It increased from 5.52 eV for Hf silicate with a Hf/Si ratio of 3:1 to 6.61 eV for Hf silicate with a Hf/Si ratio of 1:3. For Hf silicate dielectrics, the band gap is mainly determined by Hf 5d conduction-band and O 2p valence-band states, and the increase with increasing Si concentration is due to mixing with the Si 3s electrons. By quantitative analysis of REELS spectra, the dielectric functions of the thin films were also determined and expressed as a sum of oscillators. The position, strength, and width of the oscillators were determined quantitatively for the different dielectric films.

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Electronic and optical properties of (La

Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the Log-Sine integrals have been evaluated, in the existing literature on the subject, in many different ways. The main object of this paper is to show how nicely some general formulas analogous to the generalized Log-Sine integral $Ls_n^{(m)}\left(\frac{\pi}{3}\right)$ can be obtained by using the theory of Polylogarithms. Relevant connections of the results presented here with those obtained in earlier works are also indicated precisely.