Feasibility of an in situ measurement device for bubble size and distribution

The feasibility of in situ measurement device for bubble size and distribution was explored. A novel in situ probe measurement system, the EnviroCam™, was developed. Where possible, this probe incorporated strengths, and minimized weaknesses of historical and currently available real-time measurement methods for bubbles. The system was based on a digital, high-speed, high resolution, modular camera system, attached to a stainless steel shroud, compatible with standard Ingold ports on fermenters. Still frames and/or video were produced, capturing bubbles passing through the notch of the shroud. An LED light source was integral with the shroud. Bubbles were analyzed using customized commercially available image analysis software and standard statistical methods. Using this system, bubble sizes were measured as a function of various operating parameters (e.g., agitation rate, aeration rate) and as a function of media properties (e.g., viscosity, antifoam, cottonseed flour, and microbial/animal cell broths) to demonstrate system performance and its limitations. For selected conditions, mean bubble size changes qualitatively compared favorably with published relationships. Current instrument measurement capabilities were limited primarily to clear solutions that did not contain large numbers of overlapping bubbles

Resistant Hypertension Trials and Tribulations

Introduction Our case concerns a 62-year-old white woman who was referred by her general practitioner in 2012 with a long-standing history of difficult to control blood pressure (BP). She had significant past medical history including an excised meningioma and an implantable cardiac defibrillator for a single episode of polymorphic ventricular tachycardia during general anesthesia. She also had a possible diagnosis of epilepsy and tablet-controlled type-2 diabetes mellitus. On referral to our clinic she was on 5 antihypertensive medications including enalapril 40 mg daily, bisoprolol 10 mg daily, lercanidipine 10 mg daily, losartan 50 mg daily, and indapamide 2.5 mg once daily. She was also on metformin and sodium valproate. In clinic, she appeared well. She complained of occasional headaches but had no other symptom of note. She had no significant family history of high BP. On examination, she had a body mass index in the normal range and after repeated measures, her clinic BP was found to be 195/110 mm Hg. There was very little else to find on examination, including no murmurs or renal bruits. On fundoscopy, she had grade 2 hypertensive retinopathy. Baseline investigations did not reveal anything untoward. She had a normal blood count, renal function, and electrolytes. On urinalysis, she had mild proteinuria, with a urine protein-creatinine ratio of 17 (laboratory reference value 0–13 mg/mmol). Her ECG showed sinus rhythm with a normal rate, axis, and voltage. Her echocardiogram did not show any evidence of left ventricular hypertrophy, left ventricular ejection fraction was 58%, and she had evidence of mild diastolic dysfunction. Ambulatory BP monitoring (ABPM) was performed and her mean 24-hour BP was 190/105 mm Hg. The range was 118/67 to 227/127 mm Hg, with >90% of readings >140/90 mm Hg. So, here, we have a patient with a diagnosis of resistant hypertension according to the definition in the European guidelines