No abstract

Carbon nanotubes were suspended in carbon tetrachloride and placed in magnetic fields of <80.0 kOe at 310 K. Scanning electron microscopy showed that a single and free nanotube was oriented with the tube axis parallel to the fields. From the Boltzmann distribution of tube directions, the anisotropy of susceptibilities parallel (χ∥) and perpendicular (χ⊥) to the tube axis is estimated to be χ∥ − χ⊥ ∼ (9 ± 5) × 10-6 emu per mole of carbon atoms (χ⊥ < χ∥ < 0).

A detailed understanding of the left atrial (LA) anatomy in patients with atrial fibrillation (AF) would improve the safety and efficacy of the radiofrequency catheter ablation. The objective of this study was to examine the myocardial thickness under the lines of the circumferential pulmonary vein isolation (CPVI) using 64-slice multidetector computed tomography (MDCT). Fifty-four consecutive symptomatic drug-refractory paroxysmal AF patients (45 men, age 61 ± 12 years) who underwent a primary CPVI guided by a three-dimensional electroanatomic mapping system (Carto XP; Biosense-Webster, Diamond Bar, CA, USA) with CT integration (Cartomerge; Biosense-Webster) were enrolled. Using MDCT, we examined the myocardial thickness of the LA and pulmonary vein (PV) regions in all patients. An analysis of the measurements by the MDCT revealed that the LA wall was thickest in the left lateral ridge (LLR; 4.42 ± 1.28 mm) and thinnest in the left inferior pulmonary vein wall (1.68 ± 0.27 mm). On the other hand, the thickness of the posterior wall in the cases with contact between the esophagus and left PV antrum was 1.79 ± 0.22 mm (n = 30). After the primary CPVI, the freedom from AF without any drugs during a 1-year follow-up period was 78 % (n = 42). According to the multivariate analysis, the thickness of the LLR was an independent positive predictor of an AF recurrence (P = 0.041). The structure of the left atrium and PVs exhibited a variety of myocardial thicknesses in the different regions. Of those, only the measurement of the LLR thickness was associated with an AF recurrence.

Raman and infrared spectra of intact and metal-substituted chlorophyll a were observed in the solid state and in solution. Ni, Cu, Zn, and Ag were used to substitute Mg. Nine series of metal-sensitive bands were found in both the Raman and infrared spectra in the solid state. The frequencies of these metal-sensitive bands are considered to be linear functions of the Ct-N distance (Ct is the center of the chlorin ring and N is the nitrogen atom in the pyrrole ring), by analogy with the relationships established for metalloporphyrins.

The magnetic orientation of benzophenone crystals (diamagnetism) has been studied in various intensities of fields (0.0-80.0 kOe). As the field intensity is increased, the proportion of oriented crystals increases. The orientation is found to follow the Boltzmann distribution for crystals possessing different magnetic energies.