Bloch oscillations at room temperature in graphene/h-BN electrostatic superlattices.

In this manuscript, we report the fabrication and the measurements of Bloch oscillations at room temperature in electrostatic graphene/h-BN superlattices. The electrostatic superlattice consists of an array of tilted metallic electrodes deposited over graphene monolayer/h-BN monolayer grown on 2 inch wafers of doped Si/SiO2. We show the formation of minibands at room temperature, negative differential resistance and the evidence of Bloch oscillations. The experimental results are sustained by numerical modelling of these 2D superlattices. The experimental results are sustained by numerical modelling of these 2D superlattices. At room temperature, we have measured a period of Bloch oscillations of 55 meV which corresponds to a frequency of 13 THz.

Predicting Trainee Clinical Success From Performance at Simulated Endotracheal Intubation.

INTRODUCTION: Multiple attempts and failure at endotracheal intubation (ETI) are common for inexperienced practitioners and can cause patient morbidity. A test to predict a provider's likelihood of success at patient ETI could assist decisions about training. This project investigated whether trainees' performance at laryngoscopy on airway mannequins predicted their laryngoscopy outcomes in patients. METHODS: Twenty-one consenting first-year anesthesiology residents, emergency medicine residents, and medical students enrolled in this prospective, observational study. They performed laryngoscopy and ETI with a curved laryngoscope on 4 airway mannequins. Metrics included peak dental force, procedure duration, esophageal intubation, laryngeal view, and first-pass ETI success on the mannequins. Trainee data from 203 patient ETIs were collected over a roughly 2-month period centered around the simulation test. Multivariable logistic regression analyzed the relationship of mannequin metrics, participant experience, and a patient difficult airway score with trainee ETI outcomes in patients. RESULTS: Median trainee first-pass success rate at patient ETI was 63%, the rate of ETI problems was 16%, and the esophageal intubation rate was 6%. Laryngoscopy peak dental force, first-pass ETI success, and duration on individual mannequins were significant predictors of patient ETI first-pass success. Metrics from 2 of the 4 mannequins predicted ETI problems. DISCUSSION: Performance metrics from simulated laryngoscopy predicted trainee outcomes during patient ETI. First-pass success and ETI problems affect patient safety and are related to trainee skill. Mannequin laryngoscopy tests could identify trainees who would benefit from additional practice. The metrics could be surrogate end points in research to optimize simulated laryngoscopy training.

Wafer-scale graphene-ferroelectric HfO2/Ge-HfO2/HfO2 transistors acting as three-terminal memristors.

In this paper we report a set of experiments at the wafer level regarding field-effect transistors with a graphene monolayer channel transferred on the ferroelectric HfO2/Ge-HfO2/HfO2 three-layer structure. This kind of transistor has a switching ratio of 103 between on and off states due to the bandgap in graphene induced by the ferroelectric structure. Both top and back gates effectively control the carriers' charge flow in graphene. The transistor acts as a three-terminal memristor, termed a memtransistor, with applications in neuromorphic computation.

[Retroperitoneal appendicular abscess]. / Abcesul retroperitoneal de cauza apendiculara.

This article presents a 28 years old male patient case with a retroperitoneal collection of apendicular origin. After few comments about clinical and paraclinical aspects, the authors emphasise the particular aspects of differential diagnosis and surgical approach which, finally, lead to a full recovery of the patient.