RESUMEN
Devices with tunable resistance are highly sought after for neuromorphic computing. Conventional resistive memories, however, suffer from nonlinear and asymmetric resistance tuning and excessive write noise, degrading artificial neural network (ANN) accelerator performance. Emerging electrochemical random-access memories (ECRAMs) display write linearity, which enables substantially faster ANN training by array programing in parallel. However, state-of-the-art ECRAMs have not yet demonstrated stable and efficient operation at temperatures required for packaged electronic devices (~90°C). Here, we show that (semi)conducting polymers combined with ion gel electrolyte films enable solid-state ECRAMs with stable and nearly temperature-independent operation up to 90°C. These ECRAMs show linear resistance tuning over a >2× dynamic range, 20-nanosecond switching, submicrosecond write-read cycling, low noise, and low-voltage (±1 volt) and low-energy (~80 femtojoules per write) operation combined with excellent endurance (>109 write-read operations at 90°C). Demonstration of these high-performance ECRAMs is a fundamental step toward their implementation in hardware ANNs.
RESUMEN
Omiderm (Omikron Scientific Ltd., Rehovot, Israel), a new synthetic wound covering based on hydrophilized polyurethane, was found to be highly permeable to water. Values in the region of 5000 g/m2 24 h were found for the water permeability of Omiderm in comparison to 1400 and 500 g/m2 24 h for Biobrane (Hall, Woodroof Inc., Santa Ana, CA) and OP site (Smith and Nephew Ltd.), respectively. Permeabilities of antibacterial agents through Omiderm were found to be two to three orders of magnitude greater than those through Biobrane. The in vitro effectiveness of various antibacterial agents in lowering bacterial growth of different bacterial strains were applied to seeded agar plates through Omiderm membrane was investigated. NBH ointment (1% Neomycin, 1% Bacitracin, and 0.5% Hydrocortisone) was found to be the most effective material in inhibiting bacterial growth, except for Pseudomonas aeruginosa where silver sulfadiazine was superior. In in vivo experiments bacterial counts of infected wounds covered with Omiderm and topically treated with NBH were lowered to less than 10(3) organism/g tissue after one day of treatment.
Asunto(s)
Vendajes , Materiales Biocompatibles Revestidos , Poliuretanos , Infección de Heridas/prevención & control , Animales , Antibacterianos , Materiales Biocompatibles , Membranas Artificiales , Permeabilidad , Ratas , AguaRESUMEN
Eighteen months of experience with a new synthetic temporary skin substitute (Omiderm, Omikron Scientific Ltd., Rehovot, Israel) is presented. The substitute is a thin, transparent, flexible membrane. It is used when a biological dressing would otherwise have been used. Our experience consists of laboratory studies and 75 clinical cases including donor sites application, chronic wounds, ulcers, partial thickness and full thickness burns. The membrane is very elastic, permitting free movement and physiotherapy during the healing process. The material protects the wound and prevents either the accumulation of fluid under it or wound desiccation. It does not interfere with the normal healing process. It reduces pain, prevents bacterial invasion and is very easy to handle. Complications, such as haematoma formation or infection, were quite few. We recommend its use in routine daily practice.