Rationale and protocol for the Nursing and Allied Health Graduate Outcomes Tracking (NAHGOT) study: a large-scale longitudinal investigation of graduate practice destinations.

INTRODUCTION: Inequitable distribution of health workforce limits access to healthcare services and contributes to adverse health outcomes. WHO recommends tracking health professionals from their points of entry into university and over their careers for the purpose of workforce development and planning. Previous research has focused on medical students and graduates' choice of practice location. Few studies have targeted nursing and allied health graduates' practice intentions and destinations. The Nursing and Allied Health Graduate Outcomes Tracking (NAHGOT) study is investigating factors affecting Australian nursing and allied health students and graduates' choice of graduate practice location over the course of their studies and up to 10 years after graduation by linking multiple data sources, including routinely collected university administrative and professional placement data, surveys of students and graduates, and professional registration data. METHODS: By using a prospective cohort study design, each year a new cohort of about 2000 students at each participating university (Deakin University, Monash University and the University of Newcastle) is tracked throughout their courses and for 10 years after graduation. Disciplines include medical radiation practice, nursing and midwifery, occupational therapy, optometry, paramedicine, pharmacy, physiotherapy, podiatry and psychology. University enrolment data are collected at admission and professional placement data are collected annually. Students' practice destination intentions are collected via questions added into the national Student Experience Survey (SES). Data pertaining to graduates' practice destination, intentions and factors influencing choice of practice location are collected in the first and third years after graduation via questions added to the Australian Graduate Outcomes Survey (GOS). Additionally, participants may volunteer to receive a NAHGOT survey in the second and fourth-to-tenth years after graduation. Principal place of practice data are accessed via the Australian Health Practitioner Regulation Agency (Ahpra) annually. Linked data are aggregated and analysed to test hypotheses comparing associations between multiple variables and graduate practice location. RESULTS: This study seeks to add to the limited empirical evidence about factors that lead to rural practice in the nursing and allied health professions. This prospective large-scale, comprehensive study tracks participants from eight different health professions across three universities through their pre-registration education and into their postgraduate careers, an approach not previously reported in Australia. To achieve this, the NAHGOT study links data drawn from university enrolment and professional placement data, the SES, the GOS, online NAHGOT graduate surveys, and Ahpra data. The prospective cohort study design enables the use of both comparative analysis and hypothesis testing. The flexible and inclusive study design is intended to enable other universities, as well as those allied health professions not regulated by Ahpra, to join the study over time. CONCLUSION: The study demonstrates how the systematic, institutional tracking and research approach advocated by the WHO can be applied to the nursing and allied health workforce in Australia. It is expected that this large-scale, longitudinal, multifactorial, multicentre study will help inform future nursing and allied health university admission, graduate pathways and health workforce planning. Furthermore, the project could be expanded to explore health workforce attrition and thereby influence health workforce planning overall.

Surface-gate-defined single-electron transistor in a MoS2 bilayer.

We report the multi-scale modeling and design of a gate-defined single-electron transistor in a MoS2 bilayer. By combining density-functional theory and finite-element analysis, we design a surface gate structure to electrostatically define and tune a quantum dot and its associated tunnel barriers in the MoS2 bilayer. Our approach suggests new pathways for the creation of novel quantum electronic devices in two-dimensional materials.

Optical properties of a conjugated-polymer-sensitised solar cell: the effect of interfacial structure.

Dye-sensitised solar cells (DSSCs) have sparked considerable interest over two decades. Recently, a method of polymer-wire sensitisation was demonstrated; the polymer is suggested to form a hole transport pathway (wire) following initial charge separation. We predict the optical properties of this polymer in various interfacial configurations, including the effects of chain length and attachment to {100} or {101} TiO2 facets. Contrary to most DSSCs, the {100} facet model best describes the experimental spectrum, predicting a relative thickness of 5.7 ± 0.2 µm, although {101} attachment, if implemented, may improve collection efficiency. Long chains are optimal, and stable attachment sites show minimal differences to absorbance in the major solar emission (visible) band. Combinations of {100}, {101}, and pseudo-bulk TiO2 models in three-parameter fits to experiment confirm the relative importance of the {100} facet.

Ab Initio Comparison of Bonding Environments and Threshold Behavior in Ge(x)As10Se(90-x) and Ge(x)Sb10Se(90-x) Glass Models.

Ab initio models of Ge(x)As10Se(90-x), and Ge(x)Sb10Se(90-x) glasses are constructed, and their bonding environments are characterized and compared against each other and to recent experimental studies of equivalent glasses at the same stoichiometry and density. A minimum in the linear refractive index is found to correlate with a maximum in the number of length-one, predominantly Se, atomic chains for both glass types. The threshold behavior difference between GeAsSe and GeSbSe is shown to be due to the appearance of As-As-Se2 structural units beyond the MCN = 2.67 threshold in the GeAsSe glasses.

Structural modeling of Ge6.25As32.5Se61.25 using a combination of reverse Monte Carlo and Ab initio molecular dynamics.

Ternary glass structures are notoriously difficult to model accurately, and yet prevalent in several modern endeavors. Here, a novel combination of Reverse Monte Carlo (RMC) modeling and ab initio molecular dynamics (MD) is presented, rendering these complicated structures computationally tractable. A case study (Ge6.25As32.5Se61.25 glass) illustrates the effects of ab initio MD quench rates and equilibration temperatures, and the combined approach's efficacy over standard RMC or random insertion methods. Submelting point MD quenches achieve the most stable, realistic models, agreeing with both experimental and fully ab initio results. The simple approach of RMC followed by ab initio geometry optimization provides similar quality to the RMC-MD combination, for far fewer resources.

Microscopy as a statistical, Rényi-Ulam, half-lie game: a new heuristic search strategy to accelerate imaging.

Finding a fluorescent target in a biological environment is a common and pressing microscopy problem. This task is formally analogous to the canonical search problem. In ideal (noise-free, truthful) search problems, the well-known binary search is optimal. The case of half-lies, where one of two responses to a search query may be deceptive, introduces a richer, Rényi-Ulam problem and is particularly relevant to practical microscopy. We analyse microscopy in the contexts of Rényi-Ulam games and half-lies, developing a new family of heuristics. We show the cost of insisting on verification by positive result in search algorithms; for the zero-half-lie case bisectioning with verification incurs a 50% penalty in the average number of queries required. The optimal partitioning of search spaces directly following verification in the presence of random half-lies is determined. Trisectioning with verification is shown to be the most efficient heuristic of the family in a majority of cases.

A study of size-dependent properties of MoS2 monolayer nanoflakes using density-functional theory.

Novel physical phenomena emerge in ultra-small sized nanomaterials. We study the limiting small-size-dependent properties of MoS2 monolayer rhombic nanoflakes using density-functional theory on structures of size up to Mo35S70 (1.74 nm). We investigate the structural and electronic properties as functions of the lateral size of the nanoflakes, finding zigzag is the most stable edge configuration, and that increasing size is accompanied by greater stability. We also investigate passivation of the structures to explore realistic settings, finding increased HOMO-LUMO gaps and energetic stability. Understanding the size-dependent properties will inform efforts to engineer electronic structures at the nano-scale.

Rationally Designed Probe for Reversible Sensing of Zinc and Application in Cells.

Biologically compatible fluorescent ion sensors, particularly those that are reversible, represent a key tool for answering a range of fundamental biological questions. We report a rationally designed probe with a 6'-fluoro spiropyran scaffold (5) for the reversible sensing of zinc (Zn2+) in cells. The 6'-fluoro substituent overcomes several limitations normally associated with spiropyran-based sensors to provide an improved signal-to-background ratio and faster photoswitching times in aqueous solution. In vitro studies were performed with 5 and the 6'-nitro analogues (6) in HEK 293 and endothelial cells. The new spiropyran (5) can detect exogenous Zn2+ inside both cell types and without affecting the proliferation of endothelial cells. Studies were also performed on dying HEK 293 cells, with results demonstrating the ability of the key compound to detect endogenous Zn2+ efflux from cells undergoing apoptosis. Biocompatibility and photoswitching of 5 were demonstrated within endothelial cells but not with 6, suggesting the future applicability of sensor 5 to study intracellular Zn2+ efflux in these systems.

Correlating the Energetics and Atomic Motions of the Metal-Insulator Transition of M1 Vanadium Dioxide.

Materials that undergo reversible metal-insulator transitions are obvious candidates for new generations of devices. For such potential to be realised, the underlying microscopic mechanisms of such transitions must be fully determined. In this work we probe the correlation between the energy landscape and electronic structure of the metal-insulator transition of vanadium dioxide and the atomic motions occurring using first principles calculations and high resolution X-ray diffraction. Calculations find an energy barrier between the high and low temperature phases corresponding to contraction followed by expansion of the distances between vanadium atoms on neighbouring sub-lattices. X-ray diffraction reveals anisotropic strain broadening in the low temperature structure's crystal planes, however only for those with spacings affected by this compression/expansion. GW calculations reveal that traversing this barrier destabilises the bonding/anti-bonding splitting of the low temperature phase. This precise atomic description of the origin of the energy barrier separating the two structures will facilitate more precise control over the transition characteristics for new applications and devices.

Ab initio electronic properties of dual phosphorus monolayers in silicon.

IN THE MIDST OF THE EPITAXIAL CIRCUITRY REVOLUTION IN SILICON TECHNOLOGY, WE LOOK AHEAD TO THE NEXT PARADIGM SHIFT: effective use of the third dimension - in particular, its combination with epitaxial technology. We perform ab initio calculations of atomically thin epitaxial bilayers in silicon, investigating the fundamental electronic properties of monolayer pairs. Quantitative band splittings and the electronic density are presented, along with effects of the layers' relative alignment and comments on disordered systems, and for the first time, the effective electronic widths of such device components are calculated.

Ab initio calculation of valley splitting in monolayer δ-doped phosphorus in silicon.

: The differences in energy between electronic bands due to valley splitting are of paramount importance in interpreting transport spectroscopy experiments on state-of-the-art quantum devices defined by scanning tunnelling microscope lithography. Using vasp, we develop a plane-wave density functional theory description of systems which is size limited due to computational tractability. Nonetheless, we provide valuable data for the benchmarking of empirical modelling techniques more capable of extending this discussion to confined disordered systems or actual devices. We then develop a less resource-intensive alternative via localised basis functions in siesta, retaining the physics of the plane-wave description, and extend this model beyond the capability of plane-wave methods to determine the ab initio valley splitting of well-isolated δ-layers. In obtaining an agreement between plane-wave and localised methods, we show that valley splitting has been overestimated in previous ab initio calculations by more than 50%.

Different solvates of the dinuclear cyclometallated gold(I) complex [Au2(µ-2-C6H4AsMe2)2]: a computational study insight into solvent-effected optical properties.

Two solvates of an arsena-aura-metallocyclic molecule, which, apart from the different solvents, have the same molecular stoichiometry, display different optical properties. We develop an ab initio model, benchmarked against X-ray diffraction experiment, to explore the possible causes of this change in behavior. We study the bonding and electronic properties of the crystals, their local environments, and consider possible effects of the solvents used for crystallization.

Synthesis and structures of cyclic gold complexes containing diphosphine ligands and luminescent properties of the high nuclearity species.

A mixture of cyclic gold(I) complexes [Au(2)(µ-cis-dppen)(2)]X(2) (X = OTf 1, PF(6)3) and [Au(cis-dppen)(2)]X (X = OTf 2, PF(6)4) is obtained from the reaction of [Au(tht)(2)]X (tht = tetrahydrothiophene) with one equivalent of cis-dppen [dppen = 1,2-bis(diphenylphosphino)ethylene]. The analogous reaction with trans-dppen or dppa [dppa = bis(diphenylphosphino)acetylene] affords the cyclic trinuclear [Au(3)(µ-trans-dppen)(3)]X(3) (X = OTf 11, PF(6)12) and tetranuclear [Au(4)(µ-dppa)(4)]X(4) (X = OTf 13, PF(6)14, ClO(4)15) gold complexes, respectively. Recrystallization of 15 from CH(2)Cl(2)/MeOH yielded a crystal of the octanuclear gold cluster [Au(8)Cl(2)(µ-dppa)(4)](ClO(4))(2)16. Attempts to prepare dicationic binuclear gold(II) species from the reaction of a mixture of 3 and 4 with halogens gave a mixture of products, the components of which confirmed to be acyclic binuclear gold(I) [Au(2)X(2)(cis-dppen)] (X = I 5, Br 7) and cyclic mononuclear gold(III) [AuX(2)(cis-dppen)]PF(6) (X = I 6, Br 8) complexes. Complexes 11-14 reveal weak emission in butyronitrile glass at 77 K, but they are non-emissive at room temperature. Ab initio modelling was performed to determine the charge state of the gold atoms involved. Extensive structural comparisons were made to experimental data to benchmark these calculations and rationalize the conformations.