Rene G Williamson

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Few experimental and complementary theoretical studies have investigated high-frequency (>20 MHz) nonlinear responses from polymer-shelled ultrasound contrast agents. Three polymer agents with different shell properties were examined for their single-bubble backscatter when excited with a 40 MHz tone burst. Higher-order harmonic responses were observed for(More)
BACKGROUND COPD patients with chronic bronchitis include a subgroup with persistent sputum production on most or every day. We hypothesized that COPD patients with persistent sputum production have a different profile of airway inflammation, and more severe clinical characteristics. OBJECTIVE To compare the airway inflammation profile and clinical(More)
BACKGROUND Patients with severe asthma appear relatively corticosteroid resistant. Corticosteroid responsiveness is closely related to the degree of eosinophilic airway inflammation. The extent to which eosinophilic airway inflammation in severe asthma responds to treatment with systemic corticosteroids is not clear. OBJECTIVE To relate the physiological(More)
The diagnosis of pancreatic disease is often difficult because of its retroperitoneal location and the non-specific nature of abdominal pain. There is no one test which provides all the information needed, and a series of complementary tests are generally required. This article discusses the different modalities available for investigating the patient with(More)