Statistics of localized phase slips in tunable width planar point contacts.

The main dissipation mechanism in superconducting nanowires arises from phase slips. Thus far, most of the studies focus on long nanowires where coexisting events appear randomly along the nanowire. In the present work we investigate highly confined phase slips at the contact point of two superconducting leads.

Time-series analysis of long-term ambulatory myocardial ischemia: effects of beta-adrenergic and calcium channel blockade.

We have previously demonstrated the utility of time-series analysis applied to 72-hour ambulatory electrocardiographic data in patients with coronary artery disease. The present investigation applied time-series analysis to long-term (120-hour) ambulatory electrocardiographic data to determine the minimal period of monitoring needed (1) to detect periodicity of ischemia-related variables in ambulatory patients, (2) to describe auto-correlation and cross-correlation functions for heart rate and ischemia, and (3) to describe the effects of beta-adrenergic and calcium channel blockade on circadian characteristics and coupling of heart rate and ischemia. A double-blind crossover design was used to obtain 120-hour recordings during placebo, atenolol (200 mg/day), and diltiazem (360 mg/day) administration.

The impact of balloon material and lesion characteristics on the incidence of angiographic and clinical complications of coronary angioplasty.

To assess the importance of balloon material used for percutaneous transluminal coronary angioplasty (PTCA), we compared the complication rates observed with low complaint plastomer (PM 300), intermediately compliant polyethylene (PE 600), and highly compliant polyolefin copolymer (POC) balloons. In a total of 1,650 procedures, one of these balloon materials was used to dilate 2,040 lesions. The dissection rate tended to be slightly lower with the use of more compliant balloon material.

Intravascular ultrasound versus angiography for measurement of luminal diameters in normal and diseased coronary arteries.

Quantitation of coronary luminal diameter with a 20 MHz mechanically rotating intravascular ultrasound (IVUS) catheter was compared with orthogonal-view cineangiography by use of a semiautomated edge-detection algorithm in 48 patients undergoing coronary angioplasty. Quantitative comparison of 196 matched segments was attempted, but in only 174 (88.8%) was a direct comparison of the two techniques possible.

The brachial approach for intracoronary stent implantation.

Aggressive anticoagulation after intracoronary stent implantation leads to an increased incidence of femoral hematomas and vascular complications. Out of 74 Medtronic Wiktor stent implantations, six were performed via right brachial artery cut-down. All six attempts were successful without stent closure, bleeding or vascular complications.