Dual Josephson Impedance Bridge: Towards a Universal Bridge for Impedance Metrology.

This paper presents a full characterization of a Dual Josephson Impedance Bridge (DJIB) at frequencies up to 80 kHz by using the DJIB to compare the best available impedance standards that are (a) directly traceable to the quantum Hall effect, (b) used as part of international impedance comparisons, or (c) believed to have calculable frequency dependence. The heart of the system is a dual Josephson Arbitrary Waveform Synthesizer (JAWS) source that offers unprecedented flexibility in high-precision impedance measurements. The JAWS sources allow a single bridge to compare impedances with arbitrary ratios and phase angles in the complex plane.

Minimum ten-year follow-up of spinal stenosis with degenerative spondylolisthesis treated with decompression and dynamic stabilization.

Background: The Dynesys system remains the most widely implanted posterior non-fusion pedicle screw system. Various study designs used in investigations with good to excellent short- and mid-term results have been reported in the current literature. However, there is a lack of information concerning long-term outcomes following treatment for spinal stenosis with degenerative spondylolisthesis.

Restoring the Electrical Properties of CVD Graphene via Physisorption of Molecular Adsorbates.

Chemical vapor deposition (CVD) is a powerful technique to produce graphene for large-scale applications. Polymer-assisted wet transfer is commonly used to move the graphene onto silicon substrates, but the resulting devices tend to exhibit p-doping, which decreases the device quality and reproducibility. In an effort to better understand the origin of this effect, we coated graphene with n-methyl-2-pyrrolidone (NMP) and hexamethyldisilazane (HMDS) molecules that exhibit negligible charge transfer to graphene but bind more strongly to graphene than ambient adsorbents.

Spontaneous spinal epidural haematoma during Factor Xa inhibitor treatment (Rivaroxaban).

We report on a 61-year-old female patient who developed a spontaneous spinal epidural haematoma (SSEH) after being treated by rivaroxaban, a new agent for the prevention of venous thromboembolic events in orthopaedic surgery. Although the pathogenesis of SSEH is unclear, anticoagulant therapy is a known risk factor. The patient sustained a sudden onset of severe back pain in the thoracic spine, followed by paraplegia below T8, 2 days after proximal tibial osteotomy and rivaroxaban therapy.

Implant removal after posterior stabilization of the thoraco-lumbar spine.

Introduction: Implant removal because of pain after posterior fusion in the thoracic and lumbar spine is a widely performed operation. We conducted a retrospective study to examine whether patients benefit from implant removal.

Patients And Methods: 57 patients (29 males, 28 females, mean age 46.