Condylar position and mandibular function after bilateral sagittal split osteotomy

The purpose of this retrospective study was to perform an evaluation of postoperative positional changes of the condyle and mandibular function after bilateral sagittal split osteotomy (BSSO) with manual proximal segment positioning. PATIENTS: 45 patients were divided into the 2 groups 舐 G1 (advancement 舐 14 patients) and G2 (setback–31 patients). Rigid internal fixation screws were utilized in all cases. Inclusion criteria were only BSSO, no TMJ symptoms preoperatively and age 18 or older. RESULTS: The differences between pre- and postoperative condyle position were evaluated using measurements taken from preoperative CT scans and compared to CT scans made a minimum of 6 months postoperatively. The positional changes in both the axial and sagittal planes were measured and compared. The recovery of mandibular function was evaluated by measuring maximal interincisal opening (MIO). The results revealed that condylar positional changes after BSSO in both groups were minimal and not significantly different for all three dimensions measured. The recovery of mandibular function was faster in the group G2 than in the group G1

Photocatalytic splitting of water.

The use of photocatalysis for the photosplitting of water to generate hydrogen and oxygen has gained interest as a method for the conversion and storage of solar energy. The application of photocatalysis through catalyst engineering, mechanistic studies and photoreactor development has highlighted the potential of this technology, with the number of publications significantly increasing in the past few decades. In 1972 Fujishima and Honda described a photoelectrochemical system capable of generating H2 and O2 using thin-film TiO2. Since this publication, a diverse range of catalysts and platforms have been deployed, along with a varying range of photoreactors coupled with photoelectrochemical and photovoltaic technology. This chapter aims to provide a comprehensive overview of photocatalytic technology applied to overall H2O splitting. An insight into the electronic and geometric structure of catalysts is given based upon the one- and two-step photocatalyst systems. One-step photocatalysts are discussed based upon their d0 and d10 electron configuration and core metal ion including transition metal oxides, typical metal oxides and metal nitrides. The two-step approach, referred to as the Z-scheme, is discussed as an alternative approach to the traditional one-step mechanism, and the potential of the system to utilise visible and solar irradiation. In addition to this the mechanistic procedure of H2O splitting is reviewed to provide the reader with a detailed understanding of the process. Finally, the development of photoreactors and reactor properties are discussed with a view towards the photoelectrochemical splitting of H2O

EPR investigations of polymeric and H2O2 -modified C3N4 -based photocatalysts

The C3N4 -based nanopowders prepared by thermal condensation of melamine (MCN) with subsequent thermal etching (MCN-TE) and H2O2 -treatment were investigated by Q- and X-band EPR spectroscopy in dark and upon in situ UVA or visible-light exposure. Lorentzian signal at g = 2.003, more pronounced in the case of the thermally etched material, dominates EPR spectra of MCN and MCN-TE. More complex spectra were found for H2O2 -treated photocatalysts revealing the presence of signals attributed to the radicals produced via H2O2 interaction with C/N sites in the C3N4 polymeric network. The X-band spectra monitored upon in situ irradiation of the C3N4 -based photocatalysts evidenced the intensity growth of the single line at g = 2.0033 indicating the photoinduced generation of electrons in localized paramagnetic states with the Curie dependence on temperature in the temperature range 100–180 K. The response towards UV or visible-light exposure was significantly limited in the case of H2O2 -treated photocatalysts. EPR spin trapping experiments performed in aqueous suspensions demonstrated the formation of HO2[rad] and HO [rad] spin-adducts, and the increased stability of the primary photogenerated O2 javax.xml.bind.JAXBElement@3a251187 – in aprotic media was well documented by the irradiation of the photocatalysts in the dimethylsulfoxide/water mixed solvent. The highest activities in the production of the non-persistent radical species spin-adducts were found for the thermally etched and pristine photocatalysts, confirming the negative effect of H2O2 -treatment

Cerium-Doped Zirconium Dioxide, a Visible-Light-Sensitive Photoactive Material of Third Generation

The dispersion of small amounts of Ce4+ ions in the bulk of ZrO2 leads to a photoactive material sensitive to visible light. This is shown by monitoring with EPR the formation and the reactivity of photogenerated (lambda > 420 nm) charge carriers. The effect, as confirmed by DFT calculations, is due to the presence in the solid of empty 4f Ce states at the mid gap, which act as intermediate levels in a double excitation mechanism. This solid can be considered an example of a third-generation photoactive material