20 research outputs found
A metamaterial absorber for the terahertz regime: Design, fabrication and characterization
We present a metamaterial that acts as a strongly resonant absorber at
terahertz frequencies. Our design consists of a bilayer unit cell which allows
for maximization of the absorption through independent tuning of the electrical
permittivity and magnetic permeability. An experimental absorptivity of 70% at
1.3 terahertz is demonstrated. We utilize only a single unit cell in the
propagation direction, thus achieving an absorption coefficient = 2000
cm. These metamaterials are promising candidates as absorbing elements
for thermally based THz imaging, due to their relatively low volume, low
density, and narrow band response
Transmutation of singularities and zeros in graded index optical instruments: a methodology for designing practical devices
Treatment-related cardiotoxicity in survivors of childhood cancer
Treatment advances and higher participation rates in clinical trials have rapidly increased the number of survivors of childhood cancer. However, chemotherapy and radiation treatments are cardiotoxic and can cause cardiomyopathy, conduction defects, myocardial infarction, hypertension, stroke, pulmonary oedema, dyspnoea and exercise intolerance later in life. These cardiotoxic effects are often progressive and irreversible, emphasizing a need for effective prevention and treatment to reduce or avoid cardiotoxicity. Medical interventions, such as angiotensin-converting enzyme inhibitors, ÎČ-blockers, and growth hormone therapy, might be used to treat cardiotoxicity in childhood cancer survivors. Preventative strategies should include the use of dexrazoxane, which provides cardioprotection without reducing the oncological efficacy of doxorubicin chemotherapy; less-toxic anthracycline derivatives and the use of antioxidant nutritional supplements might also be beneficial. Continuous-infusion doxorubicin provides no benefit over bolus infusion in children. Identifying patient-related (for example, obesity and hypertension) and drug-related (for example, cumulative dose) risk factors for cardiotoxicity could help tailor treatments to individual patients. However, all survivors of childhood cancer are at increased risk of cardiotoxicity, suggesting that survivor screening recommendations for assessment of global risk of premature cardiovascular disease should apply to all survivors. Optimal, evidence-based monitoring strategies and multiagent preventative treatments still need to be identified