Integrated bioelectronic proton-gated logic elements utilizing nanoscale patterned Nafion

A central endeavour in bioelectronics is the development of logic elements to transduce and process ionic to electronic signals. Motivated by this challenge, we report fully monolithic, nanoscale logic elements featuring n- and p-type nanowires as electronic channels that are proton-gated by electron-beam patterned Nafion. We demonstrate inverter circuits with state-of-the-art ion-to-electron transduction performance giving DC gain exceeding 5 and frequency response up to 2 kHz. A key innovation facilitating the logic integration is a new electron-beam process for patterning Nafion with linewidths down to 125 nm. This process delivers feature sizes compatible with low voltage, fast switching elements. This expands the scope for Nafion as a versatile patternable high-proton-conductivity element for bioelectronics and other applications requiring nanoengineered protonic membranes and electrodes.

Delayed hypersensitivity reaction after cervical disc replacement: a case report

We report a case of allergic reaction after total cervical disc arthroplasty. A 52-year old woman was operated on for right C6 cervicobrachial neuralgia secondary to C5-C6 disc disease with foraminal stenosis. A cobalt-chromium-molybdenum total disc prosthesis had been implanted two years earlier. The patient was referred to our institution for recurrence of axial neck pain associated with abdominal patches of erythematous itching rash and swallowing disorder. Allergy tests confirmed type-4 allergic reaction to chromium. Symptoms decreased after removal of the prosthesis with secondary fusion. Delayed allergic reaction is uncommon in spine surgery, but should be considered in case of recurrence of initial symptomatology associated with non-spinal signs.

Linear and nonlinear model of the human middle ear

The measurement of the middle ear transfer function usually requires invasive methods. An equivalent analog equivalent model enables us to evaluate its characteristics without damaging any part of the ear. A linear and a nonlinear model of the middle ear have been developed to predict intracochlear pressure and the stapes volume velocity for various sound pressure levels (SPL). The linear model results have been compared with human eardrum impedance and middle ear transfer function data. The nonlinear phenomena due to the contraction of the stapedius muscle over 80 dB and to the stapes clipping displacement above 120 dB are represented by a set of variable electrical components. The model of the acoustic reflex is based on experimental observations. The study of the annular ligament behavior was performed on cats and extrapolated to humans with some hypothetical restrictions. These approximations provide information on the middle ear transfer function and enable us to better understand the nonlinear middle ear mechanisms in an intense acoustic field.