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Examines changes in heat treated high-alumina castables. Application of Young's modulus measurements and synchrotron radiation-energy dispersive diffraction; Analysis of the hydrate conversion process; Facilitation of sample environmental cells by fixed beam geometry.

Investigates the effect of using carbides as an antioxidant in magnesium oxide-carbon refractories. Behavior of Al[sub 8]B[sub 4]C[sub 7] in carbon monoxide gas; Evaporation of B[sub 2]O[sub 3](l) to form a liquid phase; Factors responsible for the inhibition of refractory oxidation.

Examines the influence of the grain phase on the extent and mechanism of attack of low-cement castable refractory materials with similar bond systems in a crucible slag corrosion test. Determination of general corrosion mechanism by post mortem scanning electron microscopic examination; Reaction leading to the formation of calcium hexaluminate.

Between 2005 and 2016, over 30,000 cochlear implants were implanted in Germany, while the number of retinal implants remained less than 1% of this number. The two types of retina implants that reached the market did not survive economically. The present review article discusses the impact and future of electronic retina implants in ophthalmology., Competing Interests: EZ ist einer der Gründer, Anteilseigner und der Aufsichtsratsvorsitzende der Retina Implant AG gewesen. KS arbeitete 2010 – 2015 in einem Drittmittelprojekt, das von Retina Implant AG finanziert wurde. AS war Vorstand der Retina Implant AG (in Auflösung). HF und KUBS geben an, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)

In Germany, about 30,000 to 40,000 people suffer from retinitis pigmentosa (RP), which ultimately results in blindness. The only aid to blind RP patients are retinal implants: These have been under development for several years and have now been approved as a medical product. Retinal implants produce visual perceptions in response to electrical stimulation of the degenerated retina and are useful in the everyday life of blind people. However, the currently achievable quality of vision is such that people with a retinal implant are still legally blind. The visual quality that can be achieved with epi- and subretinal implants depends not only on patient-specific factors such as individual history and status of retinal degeneration, but especially on the interface between implant and retina and the quality of the achievable neuronal activation. Biophysical approaches to functional improvements of the implants are founded on the physiology of the retina (cell density, intraretinal interconnections), are based on technical optimisation of the interface (electrode materials, size and density), and exploit the stimulation protocols with which visual information is fed into the degenerated retina (time courses of electrical stimuli, spatiotemporal stimulation pattern). Optimisation of stimulation parameters can be supported by a detailed analysis of cortical responses, with appropriate electrophysiological and optical methods. This article looks at both the physiological and biophysical fundamentals of electrical retinal stimulation, as well as the resulting retinal and cortical activation., (Georg Thieme Verlag KG Stuttgart · New York.)

Our group has developed a subretinal microphotodiode array for restoration of vision. In a clinical pilot study the array has been implanted in 11 patients suffering from photoreceptor degenerations. Here we present promising results from some of those patients where the retinal tissue above the chip was functional and the implant fulfilled its expected function. A spatial resolution of approximately 0.3 cycles/degree could be achieved with fine stripe patterns. In one subject where the implant had been placed directly under the macular region of the retina a visual acuity of 20/1000 could be measured. Artificially restored visual acuity of this quality has not been reported previously. Finally, we present images illustrating an approximation of how the visual perceptions might have appeared to the subjects, based on a mathematical model and patient reports.

Automats for patch clamping suspended cells in whole-cell configuration must (1) bring isolated cells in contact with patch contacts, (2) form gigaseals, and (3) establish stable intracellular access that allows for high quality recording of ionic currents. Single openings in planar substrates seem to be intriguing simple solutions for these problems, but due to the low rate of formation of whole-cell configurations we discarded this approach. Single openings are not suited for both attracting cells to the opening by suction and forming gigaseals with subsequent membrane rupture. To settle the three tasks with a mechanical microstructure we developed the socalled CYTOCENTERING technique to apply to suspended cells the same operation sequence as in conventional patch clamping. With this method we immobilized selected cells from a flowing suspension on the tip of a patch pipette by suction with a success rate of 97% and formed gigaseals with a success rate of 68%. Subsequent whole-cell recordings and intracellular staining with Lucifer yellow proved the stable access to the cytoplasm. Currently, a chip with an embedded suction opening in glass surrounding the microstructured contact pipette is under development. The processing of this CYTOPATCH chip is compatible to large-volume production. The CYTOPATCH automat will allow for fully automated, parallel, and asynchronous whole-cell recordings.