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Background Our goal was to clarify the comparison between elective neck dissection (END) and the wait-and-see policy in neck management for cT1N0 buccal squamous cell carcinoma (SCC). Methods This was a retrospective comparison of 175 prospectively enrolled patients with cT1N0 buccal SCC. The patients were divided into two groups based on the nonrandomized management of the neck: 125 patients received END, and 50 patients were exposed to the wait-and-see policy. The main study endpoints were locoregional control (LRC) and disease-specific survival (DSS). Patients were asked to complete the shoulder domain in the University of Washington quality of life questionnaire, version 4, 1 year postoperatively. Results Ten of the patients undergoing END developed recurrence, and the 5-year LRC rate was 92%. Five patients undergoing the wait-and-see policy developed recurrence, and the 5-year LRC rate was 90%. The difference was not significant (p = 0.668). There were 6 deaths in patients undergoing END, and the 5-year DSS rate was 94%. There were 3 deaths in patients undergoing the wait-and-see policy, and the 5-year DSS rate was 94%; the difference was not significant (p = 0.777). The mean shoulder scores of patients undergoing END and the wait-and-see policy were 93.9 and 100, respectively, and the difference was not significant (p = 0.284). Conclusion Elective neck dissection does not carry a survival benefit compared to the wait-and-see policy, and it is not suggested for patients with cT1N0 buccal SCC.

This study investigates the interaction between C 70 and X (X = H and F), and the potential energy surface of C 70 X radical. Our findings show that there are five distinct isomers of C 70 X on the surface. The calculations on the structures and energies are further discussed thermodynamically using the density function theory method at the B3LYP/6-31G (d) level. In addition, the transition states, as well as reaction pathways of X (X = H and F) transferring between different key points on C 70 representative patch, are given to explore the possible reaction mechanism. Finally, the stability of C 70 X 2 is discussed through the density functional theory.

The ferroelectric and optical properties of Bi3.25Nd0.75Ti3O12 thin films deposited on (111)Pt/Ti/SiO2/Si substrates using a chemical solution method were investigated. Bi3.25Nd0.75Ti3O12 thin films were polycrystalline and had (117) random orientation with large rod-like grains. They showed good ferroelectricity with a remnant polarization of 13.8 µC cm−2 and a coercive field of 120 kV cm−1. The dielectric constant and the dissipation factor were about 200 and 0.040, respectively, at a frequency of 10 kHz. No polarization fatigue was observed for the Pt/Bi3.25Nd0.75Ti3O12/Pt capacitor after 109 switching cycles. The optical constants (refractive index and extinction coefficient) in the wavelength range of 200–1700 nm were obtained by spectroscopic ellipsometry measurements. The optical band gap was estimated to be about 3.61 eV. The dispersion of the refractive index in the interband transition region followed the single electronic oscillator model.

Infrared optical properties of barium strontium titanate Ba0.8Sr0.2TiO3 thin films grown on Pt/Ti/SiO2/Si substrates are studied by infrared spectroscopic ellipsometry (IRSE) in the spectral range of 2.5–12.6 μm. The refractive index and extinction coefficient of Ba0.8Sr0.2TiO3 are determined by fitting the IRSE data using a classical dielectric function formula. As the wavelength increases, the refractive index decreases, but on the contrary, the extinction coefficient increases. The absorption coefficient is greater than 1000 cm−1 for the wavelength over 12.1 μm, but very small and less than 100 cm−1 under 5.3 μm. The effective static ionic charge has also been derived, which is smaller than it would be in a purely ionic material for Ba0.8Sr0.2TiO3 thin films.