First-Principles Assessment of CdTe as a Tunnel Barrier at the α-Sn/InSb Interface.

Majorana zero modes, with prospective applications in topological quantum computing, are expected to arise in superconductor/semiconductor interfaces, such as ß-Sn and InSb. However, proximity to the superconductor may also adversely affect the semiconductor's local properties. A tunnel barrier inserted at the interface could resolve this issue. We assess the wide band gap semiconductor, CdTe, as a candidate material to mediate the coupling at the lattice-matched interface between α-Sn and InSb. To this end, we use density functional theory (DFT) with Hubbard U corrections, whose values are machine-learned via Bayesian optimization (BO) [ npj Computational Materials 2020, 6, 180]. The results of DFT+U(BO) are validated against angle resolved photoemission spectroscopy (ARPES) experiments for α-Sn and CdTe. For CdTe, the z-unfolding method [ Advanced Quantum Technologies 2022, 5, 2100033] is used to resolve the contributions of different kz values to the ARPES. We then study the band offsets and the penetration depth of metal-induced gap states (MIGS) in bilayer interfaces of InSb/α-Sn, InSb/CdTe, and CdTe/α-Sn, as well as in trilayer interfaces of InSb/CdTe/α-Sn with increasing thickness of CdTe. We find that 16 atomic layers (3.5 nm) of CdTe can serve as a tunnel barrier, effectively shielding the InSb from MIGS from the α-Sn. This may guide the choice of dimensions of the CdTe barrier to mediate the coupling in semiconductor-superconductor devices in future Majorana zero modes experiments.

Hospital administrators' tolerance of staff needlestick injuries.

OBJECTIVE: To survey hospital administrators regarding their opinions of an acceptable frequency of staff needlestick injury and the frequency that would prompt additional preventive action. DESIGN: A simple anonymous questionnaire sent to 960 administrators with one reminder. Data were collected regarding hospital size and community role, whether human immunodeficiency virus (HIV)-infected patients had ever been treated, presence of an infection control practitioner, estimation of the proportion of staff vaccinated against hepatitis B, and opinions as to the acceptable frequency of needlestick accidents and the accident frequency, requiring additional action. SETTING: 240 public hospitals in New South Wales, Australia. PARTICIPANTS: The executive officers, directors of medical services, directors of nursing, and safety officers of the hospitals surveyed. RESULTS: The response rate was 50%. Administrators' opinions of acceptable accident frequency increased with hospital size and (independently of size) with experience with HIV-infected patients, and with the presence of a full-time infection control practitioner. Accident frequencies judged to require additional preventive action were higher than injury frequencies regarded as acceptable. CONCLUSIONS: The hospital administrators surveyed accept staff needlestick injuries as inevitable, the more so in hospitals that have treated known HIV-infected patients and that have full-time infection control practitioners.

Changes in drug treatment and case fatality of patients with acute myocardial infarction. Observations from the Newcastle MONICA Project, 1984/1985 to 1988/1990.

OBJECTIVE: To describe changes in medications administered to patients with acute myocardial infarction between 1984/1985 and 1988/1990 and changes in case fatality. DESIGN: Descriptive study from the Newcastle MONICA Project, which monitors all heart attacks in men and women aged 25 to 69 years in the Lower Hunter Region of New South Wales. SUBJECTS: All patients admitted to hospital with a "definite" acute myocardial infarction who survived at least 28 days during periods in 1984/1985 (513 events) and 1988/1990 (790 events). MAIN OUTCOME MEASURES: Changes in drugs being taken immediately before the onset of the myocardial infarction, prescribed during hospitalisation and on discharge from hospital, and changes in case fatality rates. RESULTS: From the first time period to the second there were significant increases in the use of aspirin, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors and hypolipidaemic agents, and significant reductions in the use of diuretics. In 1988/1990, 34% of patients with a definite myocardial infarction received thrombolytic therapy compared with fewer than 1% in 1984/1985. Among those patients who survived at least one hour from onset of symptoms, the case fatality rate declined from 13.5% to 7.9% (change -5.6%; 95% confidence limits, -8.9%, -2.2%). CONCLUSION: Large changes in drug treatment of patients with acute myocardial infarction have occurred in the second half of the 1980s. These may be responsible for the reduction in case fatality. Nevertheless, use of drugs of proven effectiveness in acute care and for secondary prevention is surprisingly low in this population.

Plans proceed to publish physician-specific data.

Physicians should be aware that the release of physician-specific information by the Pennsylvania Health Care Cost Containment Council (PHC4) may have a significant impact on decisions made by patients or potential patients. This article, which outlines PHC4's proposed Research Plan about coronary artery bypass graft (CABG) surgery and related issues, is a follow-up to "First Report Card for Physicians Due This Summer" [Pennsylvania Medicine, May 1992]

First public report for physicians due this summer.

Public reporting of physician-specific information by the Pennsylvania Health Care Cost Containment Council begins this summer with the release of a report of physician-specific surgical data. Physicians should be aware that the release of such information may have a significant impact on decisions made by patients or potential patients.

Heart attacks and the Newcastle earthquake.

OBJECTIVE: To test the hypothesis that stress generated by the Newcastle earthquake led to increased risk of heart attack and coronary death. DESIGN: A natural experiment. SUBJECTS: People living in the Newcastle and Lake Macquarie local government areas of New South Wales, Australia. INTERVENTION: At 10.27 a.m. on 28 December 1989 Newcastle was struck by an earthquake measuring 5.6 on the Richter scale. OUTCOME MEASURES: Myocardial infarction and coronary death defined by the criteria of the WHO MONICA Project and hospital admissions for coronary disease before and after the earthquake and in corresponding periods in previous years. Well established, concurrent data collection systems were used. RESULTS: There were six fatal myocardial infarctions and coronary deaths among people aged under 70 years after the earthquake in the period 28-31 December 1989. Compared with the average number of deaths at this time of year this was unusually high (P = 0.016). Relative risks for this four-day period were: fatal myocardial infarction and coronary death, 1.67 (95% confidence interval [Cl]: 0.72, 3.17); non-fatal definite myocardial infarction, 1.05 (95% Cl: 0.05, 2.22); non-fatal possible myocardial infarction, 1.34 (95% Cl: 0.67, 1.91); hospital admissions for myocardial infarction or other ischaemic heart disease, 1.27 (95% Cl: 0.83, 1.66). There was no evidence of increased risk during the following four months. CONCLUSION: The magnitude of increased risk of death was slightly less than that previously reported after earthquakes in Greece. The data provide weak evidence that acute emotional and physical stress may trigger myocardial infarction and coronary death.

Trends in ischaemic heart disease in the Hunter Region of New South Wales 1985-1989.

OBJECTIVE: To find out whether trends in rates of non-fatal myocardial infarction (MI) parallel trends in rates of coronary death. DESIGN: A population-based observational study involving continuous surveillance of all suspected heart attacks or coronary deaths from 1985 to 1989. STUDY POPULATION: Residents of the Hunter Region of New South Wales aged under 70 years. MAIN OUTCOME MEASURES: Rates of non-fatal definite or possible MI or fatal MI or coronary death, as defined by the diagnostic criteria of the WHO MONICA Project. RESULTS: For men, mortality rates declined by an average of 16.2 per 100,000 per year (95% confidence interval [CI]: -23.8, -8.7); rates of non-fatal definite MI declined by 16.2 per 100,000 (95% CI: -27.8, -4.6); rates of non-fatal possible MI increased initially and then stabilised. For women smaller changes occurred in the same directions. CONCLUSION: In this population trends in rates for non-fatal definite MI paralleled the declines in mortality rates. Rates for less severe non-fatal possible MI did not follow this pattern, perhaps reflecting increased medical attention to chest pain.