1,391 research outputs found
Proton NMR studies of the electronic structure of ZrH/sub x/
The proton spin lattice relaxation times and Knight shifts were measured in f.c.c. (delta-phase) and f.c.t. (epsilon-phase) ZrH/sub x/ for 1.5 or = to x or = to 2.0. Both parameters indicate that N(E/sub F/) is very dependent upon hydrogen content with a maximum occurring at ZrH1 83. This behavior is ascribed to modifications in N(E/sub F/) through a fcc/fct distortion in ZrH/sub x/ associated with a Jahn-Teller effect
Squamous Cell Carcinoma Metastatic to the Heart Mimicking ST-Elevation Myocardial Infarction
INTRODUCTION
Heart disease remains the leading cause of mortality in the United States, accounting for about one quarter of all deaths in 20131. Acute ischemic heart disease is a major subpopulation of this group, and typically presents with characteristic electrocardiographic (EKG) changes. The most concerning of these findings are ST-elevations, as ST Elevation Myocardial Infarction (STEMI) typically indicates the need for emergent reperfusion therapy because 30-day mortality of untreated STEMI is approximately 10-15% versus 5% in treated cases2. As a result, clinicians are taught to recognize the symptoms and signs of myocardial ischemia and STEMI in order to achieve timely reperfusion either via thrombolytic therapy within 30 minutes or percutaneous coronary intervention within 90 minutes.
However, ST-elevations may result from etiologies other than acute ischemia, and can be secondary to other acutely life-threatening pathologies or relatively benign, subacute causes. For example, ventricular aneurysms resulting from prior myocardial infarction and pericarditis can result in ST-elevation on EKG. Intracranial hemorrhage or stress (takotsubo) cardiomyopathy can also present with ST-elevations, theorized to be the result of increased catecholamines. Left ventricular hypertrophy, a sequela of poorly controlled hypertension, can also lead to J point elevations mimicking STEMI3,4. Here we review a case of unusual ST-elevation in a patient with oropharyngeal squamous cell carcinoma metastatic to the heart
Outcome and Toxicity of an Ifosfamide-Based Soft Tissue Sarcoma Treatment Protocol in Children. The Importance of Local Therapy
Background. Although the survival of children with soft tissue sarcoma (STS) has improved considerably, the outcome of patients with metastatic disease, and those with primary tumours of the extremities or parameningeal sites remains disappointing. We describe the clinical outcome of an ifosfamide-based regimen with local therapy directed only to children who failed to achieve a complete response to initial chemotherapy
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Asset liability modelling and pension schemes: the application of robust optimization to USS
This paper uses a novel numerical optimization technique - robust optimization - that is well suited to solving the asset-liability management (ALM) problem for pension schemes. It requires the estimation of fewer stochastic parameters, reduces estimation risk and adopts a prudent approach to asset allocation. This study is the first to apply it to a real-world pension scheme, and the first ALM model of a pension scheme to maximise the Sharpe ratio. We disaggregate pension liabilities into three components - active members, deferred members and pensioners, and transform the optimal asset allocation into the scheme’s projected contribution rate. The robust optimization model is extended to include liabilities and used to derive optimal investment policies for the Universities Superannuation Scheme (USS), benchmarked against the Sharpe and Tint, Bayes-Stein, and Black-Litterman models as well as the actual USS investment decisions. Over a 144 month out-of-sample period robust optimization is superior to the four benchmarks across 20 performance criteria, and has a remarkably stable asset allocation – essentially fix-mix. These conclusions are supported by six robustness checks
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