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The number (n) and diameter (d) of superheated droplets in bubble detectors of Type T-12 have been determined with high-energy heavy ions 56Fe, 84Kr and 132Xe at HIMAC accelerator in the National Institute of Radiological Sciences (NIRS), Chiba Japan. The approach to determining the number and diameter of superheated droplets is based on determination of (1) the average gap distance (g) between two neighboring bubbles in a track of high-energy heavy ion and (2) the volume ratio (VL/V) of superheated droplets to the whole volume of the detector. The volume ratio is known from preparation process of bubble detectors. The average gap distance can be obtained from the mean of gap distances measured between two neighboring bubbles in a track of heavy ion. From g and VL/V one can obtain the two basic parameters n and d of the bubble detector, which are unknown due to invisibility of superheated droplets in bubble detector. Four batches of bubble detectors of Type T-12 were calibrated by this approach. It shows that the average gap distance of bubbles in the detectors is ∼1 mm, the volume density (number n) of superheated droplets in the detectors is ∼106 cm−3 and the diameter of superheated droplets is in the range from ∼30 to 50 μm. It also shows that the two parameters n and d are different from batch to batch of the detectors when VL/V is the same. Therefore, one should make a calibration of bubble detectors at accelerator with heavy ions before using the detectors. This property is similar to that of etch track detectors (SSNTD). Keywords: Bubble detector, Number of superheated droplets, Diameter of superheated droplets, Gap distance between two neighboring bubbles in a track, Calibration of bubble detectors with heavy ions at accelerator, Grubbs criteria for rejecting parasitic erroneous data

Normal values of left ventricular function have been determined in 24 patients by means of biplane angiocardiography. Global parameters were chamber volume, ejection fraction and muscle mass. Regional ventricular function was determined by means of an orthogonal and radial axial system. Radial axis shortening parameters showed smaller standard deviations and smaller coefficient of variations than orthogonal parameters. The smallest coefficient of variation elicited regional area reduction methods. Women showed significantly lower chamber volumes and muscle mass than men. There was no difference between the two sexes in the ejection fraction and wall thickness.

According to Maxwell's model, left ventricular (LV) systolic elastic properties are characterized by a series-elastic element and LV diastolic properties by a parallel-elastic element. It is not known whether this functional concept is reflected by some morphological counterparts. In 12 patients with aortic stenosis (AS) before and 19 months after aortic valve replacement, and in ten controls, LV biplane volume and simultaneous high-fidelity pressure measurements were performed during diagnostic catheterization. The constant (k) of systolic myocardial stiffness was determined from LV peak wall stress, the maximum rate of systolic stress rise and instantaneous LV midwall circumferential fiber shortening rate at peak stress. The constant (k*; circ-1) of diastolic stiffness was assessed from the diastolic stress-stiffness relationship, using a viscoelastic model. In AS patients pre- and postoperative endomyocardial biopsies were taken to assess muscle fiber diameter, interstitial fibrosis and LV fibrous content. Systolic myocardial stiffness constant was 15 circ-1 in controls, 14 circ-1 in preoperative and 12 circ-1 in postoperative AS patients (P less than 0.01 vs. controls). Diastolic myocardial stiffness constant was 19 circ-1 in controls, 23 circ-1 in preoperative AS patients and increased slightly but not significantly to 33 circ-1 after valve replacement. Parallel to the postoperative decrease in systolic stiffness, muscle fiber diameter decreased significantly from 33 to 27 mu (P less than 0.05). The slight increase in diastolic stiffness was accompanied by a significant increase in interstitial fibrosis from 15% to 26% (P less than 0.05); LV fibrous content remained essentially unchanged after operation.(ABSTRACT TRUNCATED AT 250 WORDS)