Somatosensory evoked magnetic fields following passive finger movement

RATIONALE AND OBJECTIVES: The author introduces a number of techniques well known in exploratory pattern recognition that can be used for the analysis of the shape of metacarpophalangeal profiles. It is shown that the classic Q-scores must be adapted for such techniques to be applicable. METHODS: A new set of scores (P-scores) describing the shape of metacarpophalangeal profiles is derived. The application of various pattern-recognition techniques that use P-scores is described, using a collection of metacarpophalangeal length measurements in patients with various pathologic conditions. RESULTS: Different pattern-recognition techniques highlight different aspects of the profiles, which, when interpreted together, yield a consistent understanding of the data set and insight in individual patients' peculiarities. CONCLUSIONS: The use of scale-invariant scores is imperative when the shape of profiles is to be analyzed, especially in data sets with large variations in the scale factor. Methods of pattern recognition using such scores are of potential clinical interest.     

Occurrence of sustained increase in QT dispersion following exercise in patients with residual myocardial ischemia after healing of anterior wall myocardial infarction

Our objective was to evaluate the effect of exercise on QT dispersion over the next 3 hours, as seen on a standard 12-lead electrocardiogram in patients with healed myocardial infarction with or without residual ischemia. We measured QT and QTc dispersion before, immediately after, and 1 and 2 hours after symptom-limited, dynamic treadmill exercise tests in 28 patients with healed anterior wall myocardial infarction with (group I, n = 18) and without (group II, n = 10) residual ischemia. The same protocol was followed in 5 group I patients after successful performance of coronary angioplasty. QT and QTc dispersion did not change immediately after exercise in group II. These parameters increased in group I (QT dispersion at rest [mean +/- SD] 57 +/- 22 ms, and after exercise 87 +/- 27 ms; QTc dispersion at rest 62 +/- 25 ms, and after exercise 114 +/- 36 ms). The increases in QT and QTc dispersion were sustained for at least 2 hours. After a successful coronary angioplasty in 5 patients, these parameters no longer increased with exercise. Thus, QT dispersion increased for at least 2 hours after exercise in patients who had residual ischemia after healing of myocardial infarction. Data obtained in 5 of these patients after coronary angioplasty support the idea that residual ischemia plays a key role in the sustained increase in QT dispersion after exercise.     

Preparation of titanium nitride coated powders by rotary powder bed chemical vapour deposition

Titanium nitride coated powders were prepared by rotary powder bed chemical vapour deposition (CVD) in which a powder in a rotary specimen cell was heated by infrared radiation in a reactant gas stream. Titanium powder covered with TiN or Ti₂N thin film was obtained by diffusion coating treatment of titanium particles (grain size 10 to 50 µm) at 900 to 1000°C and 0.5 to 1.0 atm for 60 min in a nitrogen stream. TiN was coated on to the surface of scaly graphite particles (grain size 30 to 100 µm or 100 to 1000 µm) as well as titanium particles by CVD in the reactant system TiCl₄-N₂-H₂ at 900° C and 1 atm for 40 min. The uniformity of the coating (composition and film thickness) and the dispersability of the coated particles were considerably promoted by rotating the powder bed at about 90 r.p.m. compared with nonrotary powder bed CVD.     

Experimental study on thermophysicochemical properties of the LaNi5-H2 system

Thermophysicochemical properties of the LaNi₅-H₂ system are investigated for the practical utilization of hydriding alloys. The equilibrium pressure-composition isotherms are measured in full consideration of the thermal history. It is made clear that they are susceptible to the maximum temperature in operation processes. The kinetic properties are measured under isobaric and isothermal conditions. The results indicate the difference in reaction mechanism between the absorption and the desorption processes.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Crosslinking and mechanical property of liquid rubber. III. Curative effect of aralkyl and alicyclic diols

This is the third report on the relationship between the properties and the structure of polyurethane elastomers derived from hydroxyl-terminated liquid polybutadiene (HT-BD). The curative effect of low molecular weight diols was investigated. Previously it was found that the use of aromatic diols presented a processing problem because of its high melting point. To solve this problem, the use of aralkyl diols and alicyclic diols was examined in this paper. The processability was significantly improved by the use of these diols, and the elastomers obtained retained considerably high mechanical properties.