Theories in and of Mathematics Education

Mathematics Education; Learning; Teachin

Cardiovascular magnetic resonance risk stratification in patients with clinically suspected myocarditis

BACKGROUND: The diagnosis of myocarditis is challenging due to its varying clinical presentation. Since myocarditis can be associated with significant 5-year mortality, and postmortem data show myocarditis in almost 10% of all adults suffering sudden cardiac death, individual risk stratification for patients with suspected myocarditis is of great clinical interest. We sought to demonstrate that patients with clinically suspected myocarditis and a normal cardiovascular magnetic resonance (CMR) according to our definition have a good prognosis, independent of their clinical symptoms and other findings. METHODS: Prospective clinical long-term follow-up of consecutive patients undergoing CMR for work-up of clinically suspected myocarditis at our institution in 2007-2008. RESULTS: Follow-up was available for n = 405 patients (all-comers, 54.8% inpatients, 38% outpatient referrals from cardiologists). Median follow-up time was 1591 days. CMR diagnosis was “myocarditis” in 28.8%, “normal” in 55.6% and “other pathology” in 15.6%. Normal CMR was defined as normal left ventricular (LV) volumes and normal left ventricular ejection fraction (LV-EF) in the absence of late Gadolinium Enhancement (LGE). The overall mortality was 3.2%. There were seven cardiac deaths during follow-up, in addition one aborted SCD and two patients had appropriate internal cardioverter defibrillator (ICD) shocks – all of these occurred in patients with abnormal CMR. Kaplan-Meier analysis with log-rank test showed significant difference for major adverse cardiac events (cardiac death, sudden cardiac death (SCD), ICD discharge, aborted SCD) between patients with normal and abnormal CMR (p = 0.0003). CONCLUSION: In our unselected population of consecutive patients referred for CMR work-up of clinically suspected myocarditis, patients with normal CMR have a good prognosis independent of their clinical symptoms and other findings

Colorectal cancer testing rates after implementation of an organised screening programme in Vaud, Switzerland

AIMS OF THE STUDY: Canton Vaud, Switzerland, implemented an organised colorectal cancer  screening programme with colonoscopy and faecal occult blood tests in 2015, 4 to 6 years ahead of neighbouring cantons. Before its implementation, nearly half of Swiss citizens were already up to date with screening, primarily from opportunistic colonoscopies. We hypothesised that earlier implementation of an organised programme would be associated with greater increases in colorectal cancer testing rates. METHODS: We analysed Swiss health insurance claim data from CSS, a Swiss health insurer covering 16% of the Swiss population and 10% of canton Vaud. We stratified 50–69-year-olds into groups from Vaud, its four neighbouring cantons (Fribourg, Geneva, Neuchâtel and Valais), and the rest of Switzerland. We analysed overall, faecal occult blood test and colonoscopy testing rates for each year between 2010 and 2018. RESULTS: The overall testing rate increased from 7.6% in 2010 to 11.6% in 2018 (+4.0%) in Vaud, from 6.1% to 9.3% (+3.2%) in neighbouring cantons and from 7.4% to 8.6% (+1.2%) in the rest of Switzerland. The faecal occult blood test rate increased between 2016 and 2018 from 2.9% to 4.1% (+1.2%) in Vaud and from 1.7% to 2.6% (+0.9%) in neighbouring cantons, but it decreased from 3.1% to 1.5% (–1.6%) in the rest of Switzerland. The colonoscopy rate increased in all cantons, from 4.7% to 7.5% in Vaud (+2.8%), from 4.4% to 6.7% in neighbouring cantons (+2.3%) and from 4.3% to 7.1% in the rest of Switzerland (+2.8%). By 2018, 40% of faecal occult blood tests and 26% of colonoscopies in Vaud occurred in the organised programme. Those who completed an faecal occult blood test within the Vaud programme were younger, had fewer comorbidities and were more likely to have a high-deductible health plan than those tested outside the programme. CONCLUSIONS: Colorectal cancer testing rates increased between 2010 and 2018, with greater absolute increases in Vaud than in neighbouring cantons or the rest of Switzerland. Faecal occult blood test use increased in both Vaud and neighbouring cantons, possibly reflecting changes in testing patterns by general practitioners. By 2018, 40% of colonoscopies and 26% of faecal occult blood tests occurred within the screening programme

Dislocation toughening in single‐crystal KNbO₃

The growing research interest in dislocation‐tuned functionality in ceramics is evident, with the most recent proofs‐of‐concept for enhanced ferroelectric properties, electrical conductivity, and superconductivity via dislocations. In this work, we focus on dislocation‐tuned mechanical properties and demonstrate that, by engineering high dislocation densities (up to 10¹⁴ m⁻²) into KNbO₃ at room temperature, the fracture toughness can be improved by a factor of 2.8. The microstructures, including dislocations and domain walls, are examined by optical microscopy, electron channeling contrast imaging, piezo‐response force microscopy, and transmission electron microscopy methods to shed light on the toughening mechanisms. In addition, high‐temperature (above the Curie temperature of KNbO₃) indentation tests were performed to exclude the influence of ferroelastic toughening, such that the origin of the toughening effect is pinpointed to be dislocations

Lessons Learned from the European Cardiovascular Magnetic Resonance (EuroCMR) Registry Pilot Phase

The data from 11,040 patients of the European Cardiovascular Magnetic Resonance (EuroCMR) registry pilot phase offer the first documentation of the clinical use of CMR in a routine setting. The pilot data show that CMR is frequently performed in clinical practice, is a safe procedure with excellent image quality, and has a strong impact on patient management. In the future, the EuroCMR registry will help to set international benchmarks on appropriate indications, quality, and safety of CMR. In addition, outcome and cost effectiveness will be addressed on an international level in order to develop optimized imaging-guided clinical pathways and to avoid unnecessary or even harmful testing