Publications by authors named "Greenaway M"

Coulomb drag between adjacent electron and hole gases has attracted considerable attention, being studied in various two-dimensional systems, including semiconductor and graphene heterostructures. Here we report measurements of electron-hole drag in the Planckian plasma that develops in monolayer graphene in the vicinity of its Dirac point above liquid-nitrogen temperatures. The frequent electron-hole scattering forces minority carriers to move against the applied electric field due to the drag induced by majority carriers.

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2D semiconductors can drive advances in quantum science and technologies. However, they should be free of any contamination; also, the crystallographic ordering and coupling of adjacent layers and their electronic properties should be well-controlled, tunable, and scalable. Here, these challenges are addressed by a new approach, which combines molecular beam epitaxy and in situ band engineering in ultra-high vacuum of semiconducting gallium selenide (GaSe) on graphene.

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We investigate the quantum-classical correspondence for a particle tunnelling through a periodic superlattice structure with an applied bias voltage and an additional tilted harmonic oscillator potential. We show that the quantum mechanical tunnelling rate between neighbouring quantum wells of the superlattice is determined by the topology of the phase trajectories of the analogous classical system. This result also enables us to estimate, with high accuracy, the tunnelling rate between two spatially displaced simple harmonic oscillator states using a classical model, and thus gain new insight into this generic quantum phenomenon.

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We use phenomenological modelling and detailed experimental studies of charge carrier transport to investigate the dependence of the electrical resistivity,, on gate voltage,, for a series of monolayer graphene field effect transistors with mobilities,, ranging between 5000 and 250 000 cmVsat low-temperature. Our measurements over a wide range of temperatures from 4 to 400 K can be fitted by the universal relationμ=4/eδnmaxfor all devices, whereρmaxis the resistivity maximum at the neutrality point andis an 'uncertainty' in the bipolar carrier density, given by the full width at half maximum of the resistivity peak expressed in terms of carrier density,. This relation is consistent with thermal broadening of the carrier distribution and the presence of the disordered potential landscape consisting of so-called electron-hole puddles near the Dirac point.

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In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy, whereas the filled bands underneath contribute little to conduction. Here, we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity.

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Objective: To describe the case of a 17-year-old transgender boy who experienced breast development while on testosterone, having been suppressed with a gonadotropin-releasing hormone (GnRH) agonist prior to testosterone therapy.

Case Report: A 17-year-old transgender boy presented with breast development after having been on a GnRH agonist and then testosterone since the age of 11 years, having never experienced breast development before, which was consistent with pubertal gynecomastia. A small decrease in the testosterone dose resulted in a significant reduction of gynecomastia.

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Oscillatory magnetoresistance measurements on graphene have revealed a wealth of novel physics. These phenomena are typically studied at low currents. At high currents, electrons are driven far from equilibrium with the atomic lattice vibrations so that their kinetic energy can exceed the thermal energy of the phonons.

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Background: Myocarditis is an inflammatory heart disease caused by viral infections that can lead to heart failure, and occurs more often in men than women. Since animal studies have shown that myocarditis is influenced by sex hormones, we hypothesized that endocrine disruptors, which interfere with natural hormones, may play a role in the progression of the disease. The human population is exposed to the endocrine disruptor bisphenol A (BPA) from plastics, such as water bottles and plastic food containers.

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Background: Access to transgender care in Canada is poor. Although primary care providers are ideally positioned to initiate care, many feel uncomfortable providing transgender care. This study aimed to explore the impact of an electronic consultation (eConsult) service between primary care providers and transgender care specialists on access to care and to explore the content of clinical questions that were asked.

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Purpose: To establish the magnetic resonance imaging (MRI) and operative incidence of ramp lesions in a consecutive group of patients who had undergone anterior cruciate ligament reconstruction (ACLR) and to propose a graded radiologic classification that seeks to define key preoperative features that most strongly correlate with arthroscopically confirmed ramp lesions.

Methods: After retrospective review, all consecutive patients who underwent ACLR with preoperative MRI over a 16-month period were included in the study. Diagnostic arthroscopy with direct visualization of the posteromedial compartment was used to establish the true incidence of ramp lesions.

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Article Synopsis
  • Take-home naloxone (THN) interventions effectively prevent overdose deaths, but their use in Australia is still low; this project aimed to create a model (ORTHN) specifically for opioid users attending treatment and health services.* -
  • The ORTHN model involved training clients and providing naloxone via a collaborative effort from service providers and health workers; it was implemented in over 15 services in New South Wales, with evaluations done on participants' knowledge and experiences before and after the intervention.* -
  • Results showed positive outcomes with improved attitudes toward overdose response, a significant number of participants successfully reversing overdoses, and an indication of willingness to access THN services, suggesting that the ORTHN model could effectively promote
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Myocarditis is an inflammatory heart disease that leads to dilated cardiomyopathy (DCM) and heart failure. Sex hormones play an important role in the development of myocarditis with testosterone driving disease in males and estrogen being cardioprotective in females. The human population is widely exposed to the endocrine disruptor bisphenol A (BPA) from plastics such as water bottles, plastic food containers, copy paper, and receipts.

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Van der Waals materials and their heterostructures offer a versatile platform for studying a variety of quantum transport phenomena due to their unique crystalline properties and the exceptional ability in tuning their electronic spectrum. However, most experiments are limited to devices that have lateral dimensions of only a few micrometres. Here, we perform magnetotransport measurements on graphene/hexagonal boron-nitride Hall bars and show that wider devices reveal additional quantum effects.

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We discuss the trapping of cold atoms within microscopic voids drilled perpendicularly through the axis of an optical waveguide. The dimensions of the voids considered are between 1 and 40 optical wavelengths. By simulating light transmission across the voids, we find that appropriate shaping of the voids can substantially reduce the associated loss of optical power.

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Introduction: Postpartum haemorrhage (PPH) is a leading cause of maternal morbidity and mortality worldwide. Protocols for the use of prophylactic uterotonics in strategy to prevent PPH have been implemented for in-hospital births following recommendation from the National Institute for Health and Care Excellence (NICE). There are currently no guidelines for prophylactic uterotonic use in out-of-hospital (OOH) births by ambulance crews despite inappropriate birthing conditions and difficulties in obtaining a timely response from community midwives.

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Background Myocarditis is an important cause of acute and chronic heart failure. Men with myocarditis have worse recovery and an increased need for transplantation compared with women, but the reason for the sex difference remains unclear. Elevated sera soluble (s) ST2 predicts mortality from acute and chronic heart failure, but has not been studied in myocarditis patients.

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Chirality is a fundamental property of electrons with the relativistic spectrum found in graphene and topological insulators. It plays a crucial role in relativistic phenomena, such as Klein tunneling, but it is difficult to visualize directly. Here, we report the direct observation and manipulation of chirality and pseudospin polarization in the tunneling of electrons between two almost perfectly aligned graphene crystals.

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We observe a series of sharp resonant features in the differential conductance of graphene-hexagonal boron nitride-graphene tunnel transistors over a wide range of bias voltages between 10 and 200 mV. We attribute them to electron tunneling assisted by the emission of phonons of well-defined energy. The bias voltages at which they occur are insensitive to the applied gate voltage and hence independent of the carrier densities in the graphene electrodes, so plasmonic effects can be ruled out.

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Background: A major potential barrier for studying behavioral interventions for patients with Mild Cognitive Impairment (MCI) is the willingness and ability of people to enroll in and adhere to behavioral interventions, especially when the intervention involves dyads of patients with MCI and support partners. Details regarding recruitment strategies and processes (such as number of dyads screened) are often missing from reports of behavioral trials. In addition, reports do not detail the reasons a potentially eligible candidate opts out of participation in a research study.

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Recent developments in the technology of van der Waals heterostructures made from two-dimensional atomic crystals have already led to the observation of new physical phenomena, such as the metal-insulator transition and Coulomb drag, and to the realization of functional devices, such as tunnel diodes, tunnel transistors and photovoltaic sensors. An unprecedented degree of control of the electronic properties is available not only by means of the selection of materials in the stack, but also through the additional fine-tuning achievable by adjusting the built-in strain and relative orientation of the component layers. Here we demonstrate how careful alignment of the crystallographic orientation of two graphene electrodes separated by a layer of hexagonal boron nitride in a transistor device can achieve resonant tunnelling with conservation of electron energy, momentum and, potentially, chirality.

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We investigate the effects of a linear resonator on the high-frequency dynamics of electrons in devices exhibiting negative differential conductance. We show that the resonator strongly affects both the dc and ac transport characteristics of the device, inducing quasiperiodic and high-frequency chaotic current oscillations. The theoretical findings are confirmed by experimental measurements of a GaAs/AlAs miniband semiconductor superlattice coupled to a linear microstrip resonator.

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Objective: This study describes the prevalence of walking and cycling to work in New South Wales (NSW) from 2005-2010. It examines the demographic characteristics of those people walking and cycling to work and the association of walking and cycling with body mass index (BMI).

Methods: Data from the NSW Continuous Health Survey, a telephone survey of health indicators among a representative sample of residents aged 16 years or over, were used.

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A lifestyle-modification telephone-based service is delivered in New South Wales (NSW; the Get Healthy Information and Coaching Service (GHS)) as an important obesity-prevention, population-wide program. The present study examined referrals from general practitioners (GP) versus self-referral to the GHS in terms of risk profile and effectiveness of outcomes. The study used a pre-post test design to assess changes in outcomes within the setting of a telephone-based lifestyle-support service available to NSW adults (18+ years) who self-referred or were referred by their health practitioner and/or GP, and registered for the GHS between February 2009 and August 2013 (n = 22 183).

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Background: Postoperative residual neuromuscular blockade (RNMB) is associated with significant morbidity.

Objective: The aim of this retrospective data analysis was to investigate the influence of the method of RNMB reversal on postoperative outcome.

Setting: Tertiary teaching hospital in Western Australia.

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