Nanoscale Electrostatic Control of Oxide Interfaces

We develop a robust and versatile platform to define nanostructures at oxide interfaces via patterned top gates. Using LaAlO$_3$/SrTiO$_3$ as a model system, we demonstrate controllable electrostatic confinement of electrons to nanoscale regions in the conducting interface. The excellent gate response, ultra-low leakage currents, and long term stability of these gates allow us to perform a variety of studies in different device geometries from room temperature down to 50 mK. Using a split-gate device we demonstrate the formation of a narrow conducting channel whose width can be controllably reduced via the application of appropriate gate voltages. We also show that a single narrow gate can be used to induce locally a superconducting to insulating transition. Furthermore, in the superconducting regime we see indications of a gate-voltage controlled Josephson effect.Comment: Version after peer review; includes additional data on superconductivit

Clinical effect of a constant rate infusion of alfaxalone in isoflurane-anesthetized goats undergoing an experimental procedure : a pilot study

Alfaxalone is a synthetic neurosteroid anesthetic agent widely used in veterinary medicine, with a wide margin of safety and good quality of anesthesia. Also, alfaxalone has rapid biotransformation and a low tendency to accumulate in the tissues after repeated doses, which favors its intravenous use as a constant rate infusion. The aim of the study was to assess the isoflurane-sparing property and the clinical effects on the cardiorespiratory system of alfaxalone used as constant rate infusion in goats. Three healthy female goats were included in the study. Each goat was anesthetized twice (interval fifteen days) and received the following treatments in a random order during maintenance of anesthesia: 1. alfaxalone administered as a constant rate infusion at 0.05 mg/kg/min (treatment A); 2. NaCl 0.9% solution at an identical infusion rate (treatment B). Isoflurane vaporizer settings were adjusted according to a flow-chart. The SpO2 was significantly lower during treatment B than during treatment A. Although no significant differences were demonstrated for the other variables (heart rate, etc.), a clinical effect was noticed, including a modest decrease in the expired isoflurane concentration with treatment A. In conclusion, the co-administration of alfaxalone in isoflurane-anesthetized goats seems to result in only minimal side effects on cardiorespiratory parameters and may reduce the isoflurane requirements, but further studies are needed to confirm these results