Rapid fabrication of teflon apertures by controlled high voltage pulses for formation of free standing planar lipid bilayer membrane.

Free standing artificial lipid bilayers are widely used in the study of biological pores. In these types of studies, the free standing planar lipid bilayer is formed over a micron-sized aperture consisting of either polymer such as Polytetrafluoroethylene (PTFE, Teflon) or glass. Teflon is chemically inert, has a low dielectric constant, and has a high electrical resistance which combined allow for obtaining low noise recordings. This study investigates the reproducible generation of micropores in the range of 50-100 microns in diameter in a Teflon film using a high energy discharge set-up. The discharger set-up consists of a microprocessor, a transformer, a voltage regulator, and is controlled by a computer. We compared two approaches for pore creation: single and multi-pulse methods. The results showed that the multi-pulse method produced narrower aperture size distributions and is more convenient for lipid bilayer formation, and thus would have a higher success rate than the single-pulse method. The bilayer stability experiments showed that the lipid bilayer lasts for more than 33 h. Finally, as a proof-of-concept, we show that the single and multi-channel electrophysiology experiments were successfully performed with the apertures created by using the mentioned discharger. In conclusion, the described discharger provides reproducible Teflon-pores in a cheap and easy-to-operate manner.

Clinical trials of 3D printing splints to avoid contracture development in burned children

Background/aim: We evaluated the feasibility of producing splints with 3D printer technology to prevent contractures in burned children in our clinical prospective study. Materials and methods: After approvals, children with burns greater than 2nd degree were included in the study. Age, sex, burn percentages, printing time, filament types, number of filament trials, splint suitability, patient and doctor comments, preclinical trials' significances and financial impact were evaluated statistically. Results: Seventy-six trials were conducted on 18 patients. Fourteen of the patients were male and 4 are female. Average ages of boys and girls were 5 and 3, respectively. Burn percentage was 36.9 ± 13. Polylactic acid (PLAFlex), polyurethane (PolyFlex), semiflexible copolyester (nGenFlex), and thermoplastic polyurethane (TPU) were the main filaments that were used in the study. Printing time differed from 4 to 29 h according to body regions. Splints were suitable for 81.25% in upper extremity, for 66.7% in lower extremity, and for 100% in mouth. Burn percentage was significantly correlated with total number of filament (p = 0.049). Other statistical evaluations were insignificant. Conclusion: The 3D printer seems to be useful in children with burns. However, difficulties caused by some reasons like production must be overcome. By increasing clinical experience, this emerging custom-made technology may become standard, and documented problems can be solved.

Optical and structural properties of nanostructured CuIn0.7Ga0.3(Se(1-x)Te(x))2 chalcopyrite thin films--effect of stoichiometry and annealing.

The aim of this work was to study the dependence of the optical, structural and morphological properties of CuIn0.7Ga0.3(Se(1-x)Te(x))2 (briefly CIGSeTe) thin films for two different stoichiometries (for x = 0.2 and 0.8). The films have been deposited onto soda lime glass (SLG) substrates by the e-beam evaporation technique. The films showed high absorption and revealed optical band gaps ranging from 1.17 eV to 1.06 eV for x = 0 with highest annealing temperatute at 525 degrees C and 1.12 eV to 1.02 eV for x = 0.8 and with highest annealed temperature at 600 degrees C. These results were correlated with the microstructural analysis by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray diffractometry (XRD). The linear dependence of the lattice parameters as a function of Se and Te contents was examined. X-ray diffraction analyses showed that the films had the single phase chalcopyrite structure. The lattice parameters (a and c) varied linearly with the increase in Te content x from x = 0.2 to x = 0.8. The peak correspondng to the (1 1 2) plane orientation of the films increased with annealing process. Also, SEM images showed that both the grains size and the RMS (root mean square) values increased with annealing and higher Te amount that caused grains aggregation. The relative 600 degrees C elemental composition present in the deposited CIGS films have been measured by using energy dispersive X-ray analysis (EDX).